Body Area Network Applications Research Articles

Bending and SAR analysis on UWB wearable MIMO antenna for on-arm WBAN applications

Abstract Here, a planar Ultra-Wideband (UWB) wearable Multiple Input Multiple Output (MIMO) antenna is designed for on-arm wearable Wireless Body Area Network (WBAN) applications. This antenna is designed on a 100% cotton cloth substrate. The two-port MIMO antenna has a dual spinning wheel shape like radiators with the partial ground and microstrip feedings. The two partial grounds are connected to a rectangular strip to have common ground. The complete surface area of the antenna is 40 × 70 mm2. In comparison with recently published papers in the same research area, the bending and SAR analysis are also done to estimate the performance of this wearable antenna, which is the novelty of this research work. For entire UWB bandwidth, S–parameters, gain, efficiency, and diversity parameters (Channel Capacity Loss [CCL] and Envelope Correlation Coefficient [ECC]) and far-field simulations are done for all cases such as flat, bend, on body antenna, which demonstrates the appropriateness of the presented antenna to be operated to the human arm.

A chronological review of circularly polarized dielectric resonator antenna: Design and developments

This article presents a chronological overview of circularly polarized dielectric resonator antennas (CPDRAs). This article provides a comprehensive review about innovation and rapid developments of CPDRAs over the last three and half decades since 1986s. The objective of this article is to highlight the basic concept of CP mechanism in DRA and state-of-the-art developments of CPDRAs in terms of single and multi-point feed for unmodified and modified DR geometries considering different types of excitation mechanism such as microstrip line, coaxial probe, and aperture coupled feed. To give insights into circular polarization, Authors proposed a compact modified CPDRA. It offers simulated bandwidth of 47.5% (2.34-3.80 GHz), measured impedance bandwidth of 50.8% (2.26-3.78), and simulated axial bandwidth of 13% (3.29-3.75 GHz) respectively. Other antenna parameters such as peak realized gain and radiation efficiency are 7.7 dBi and 98% within operating frequency bands, respectively. The proposed outcomes confirm that the proposed CPDRA can be used as a suitable candidate for wireless body area network applications.

Performance and Analysis of UWB Aesthetic Pattern Textile Antenna for WBAN Applications

This article proposes a new aesthetic pattern-three petal flower patch antenna that operates at Ultra Wide Band (UWB) for Wireless Body Area Network (WBAN) applications. The flower structure consists of three petals and a center circle patch with the partial ground plane at the bottom. A double-sided copper-coated conductive fabric, which is 0.08 mm thick, having a surface resistivity of 0.05 Ω/square, serves as the antenna patch and ground material. This conductive patch is placed in a denim jeans material with 1mm thick that forms the substrate. The utilization of a two-layer substrate and partial ground method enhances the impedance bandwidth of the antenna. The size of the antenna is 60 mm × 60 mm × 2.16 mm. The reflection coefficient, gain, efficiency, radiation pattern, and effects of bending were the various parameters analyzed for the flower antenna. The antenna radiates from 3 to 12 GHz, which covers the entire UWB frequency range from 3.1 to 10.6 GHz assigned by Federal Communications Commission (FCC). The measurement results validate the performance of a flower patch antenna.

On the Report of Performance Analysis of Electrospun Carbon Nanofibers based Strain Sensor for Applications in Human Motion Monitoring

Flexible and wearable sensors are currently being extensively used in versatile applications including wireless body area network. Specifically, such sensors are mostly incorporated to yield a linear response within their range of operations. A recently developed flexible and wearable resistive strain sensor made of electrospun carbon nanofibers has been reported with a gauge factor up to 72. In this paper, the performance of the strain sensor embedded in a polyurethane matrix was studied at first. A linear region of operation of such sensor was defined from direct measurements for wireless body area network applications. The equivalent analytical expressions were established and reported.

A Biologically Inspired Algorithm for Low Energy Clustering Problem in Body Area Network

The growing application of body area networks (BANs) in different fields makes the low energy clustering a paramount issue. A clustering optimization algorithm in BANs is a fundamental scheme to guarantee that the essential collected data can be forwarded in a reliable path and improve the lifetime of BANs. Low energy clustering is a technique, which provides a method that shows how to reduce network communication costs in BANs. A careful low energy clustering scheme is one of the most critical means in the research of BANs, which has attracted considerable attention, comprising monitoring capability constraints. However, the classical clustering method leads to high cost when constraints such as large overall energy consumption are undertaken. Hence, a binary immune hybrid artificial bee colony algorithm (BIHABCA), a randomized swarm intelligent scheme applied in BANs, motivated by immune theory and hybrid scheme is introduced. Furthermore, we designed the formulation that considers both distances between two nodes and the length of bits. Finally, we have compared the energy cost optimized by BIHABCA with a shuffled frog leaping algorithm, ant colony optimization, and simulated annealing in the simulation with different quantity of nodes in terms of energy cost. Results show that the energy cost of the network optimized by the proposed BIHABCA method decreased compared to those by the other three methods which mean that the proposed BIHABCA finds the global optima and reduces the energy cost of transmitting and receiving data in BANs.

Design and Analysis of Modified UWB Mono-Cone Antenna for WBAN Applications

A low-profile UWB antenna is presented in this paper for wireless body area network (WBAN) applications. The proposed antenna consists of a modified mono-cone structure by adding a semi-sphere on top of the mono-cone. A top-plate is added as overhead to the proposed antenna. This plate leads to a height reduction when compared to conventional mono-cone antennas. In this paper, the effect of ground plane dimensions, effect of top-plate dimensions, effect of the supporting legs and effect of the total height of the antenna is studied to get a better insight into the working of the radiating structure. The antenna operates in the frequency range of 4.1 GHz to 10.1GHz with return loss less than -10dB. The bandwidth of the proposed antenna is 6 GHz. The frequency domain results are obtained by simulating the design using Ansoft HFSS. The voltage standing wave ratio is less than 2 within the frequency range of the proposed antenna design. The influence of the human proximity on the antenna was simulated by placing the proposed antenna over a human body model.

Metamaterial-based wearable flexible elliptical UWB antenna for WBAN and breast imaging applications

This paper presents a metamaterial-based flexible wearable ultra-wideband (UWB) antenna for breast imaging and wireless body area network (WBAN) applications. The wearable antenna is required to be a planar and low-profile structure using flexible materials. The proposed antenna comprises two layers of denim (10 × 10 mm2) and felt (10 × 15 mm2). The antenna was integrated with six metamaterial unit cells using a modified grain rice shape within a split ring resonator to enhance the bandwidth, gain, and directivity and reduce the specific absorption rate value to less than 2 W/kg. The proposed antenna operates within a broad bandwidth range (6.5 GHz–35 GHz) with the maximum gain and directivity of 8.85 dBi and 10 dBi, respectively, and a radiation efficiency of more than 70% over its operating frequency band. The results verified good agreement between the simulation and measurement of the proposed technique in detecting an existing tumor with a diameter of 4 mm from any location inside the breast. The results convincingly proved the capability of the proposed wearable UWB antenna system for both WBAN and breast imaging applications.

A Hybrid Mutual Coupling Reduction Technique in a Dual-Band MIMO Textile Antenna for WBAN and 5G Applications

This paper presents a hybrid mutual coupling reduction technique applied onto a dual-band textile MIMO antenna for wireless body area network and 5G applications. The MIMO antenna consists of two hexagonal patch antennas, each integrated with a split-ring (SR) and a bar slot to operate in dual-band mode at 2.45 GHz and 3.5 GHz. Each patch is dimensioned at $47.2 \times 31$ mm2. This hybrid technique results in a simple structure, while enabling significant reduction of mutual coupling (MC) between the closely spaced patches (up to $0.1\lambda$ ). This technique combines a line patch and a patch rotation technique, explained as follows. First, a line patch is introduced at an optimized distance to enable operation with a broad impedance bandwidth at both target frequencies. One of the patches is then rotated by 90° at an optimized distance, resulting in a significant MC suppression while maintaining the dual and broad impedance bandwidth. The proposed MIMO antenna is further evaluated under several bending configurations to assess its robustness. A satisfactory agreement between simulated and measured results is observed in both planar and bending conditions. Results show that the MIMO antenna achieves an impedance bandwidth of 4.3 % and 6.79 % in the 2.45 GHz and 3.5 GHz band, respectively. Moreover, very low MC ( $S_{21} dB) is achieved, with a low ( $x$ - and $y$ -axes, the antenna bent maintained a realized gain of 1.878 dBi and 4.027 dBi in the lower and upper band, respectively. A robust performance is offered by the antenna against the lossy effects of the human body with good agreements between simulated and measured results.

Performance Investigations of a Quad-band Microstrip Antenna for Body Wearable Wireless Devices

This research work proposes a microstripbased quad-band monopole antenna for body Wearable Wireless Devices (WWD) for Wireless Body Area Network (WBAN) applications. Ultra high frequency (UHF) and Ultra wide band (UWB) technology have been known for their efficiency to meet power, size and distance considerations for WBANs. The designed antenna resonates at four frequencies, 1.8, 2.4, 5.0 and 8.9 GHz covering licensed and license-free wireless technologies. The antenna design considers the electromagnetic (EM) effects due to the interaction of body tissues with the radio frequency (RF) waves, which are very different when compared to their interaction with free space. The performance of the antenna is investigated in terms of radiation efficiency, total gain, specific absorption rate (SAR), and thermal effects (short and long term). A simplified, human body tissue layer model is used for simulations utilizing EM computations. Simulated and experimental results are paralleled and are found to be in good agreement.

PHY-DTR: An Efficient PHY based Digital Transceiver for Body Coupled Communication using IEEE 802.3 on FPGA Platform

Body coupled communication (BCC) is an efficient networking approach to body area network (BAN) based on Human-centric communication. The BCC provides interference only between humans in very close proximity. In this work, an efficient Physical layer (PHY) based digital transceiver) is designed for BCC. The digital transceiver Module mainly contains a Digital transmitter (TX) with Manchester encoder, clock synchronization unit, and Digital receiver (RX) with Manchester decoder. The TX and RX modules are designed using a finite state machine as per the IEEE 802.3 Standards. The complete work is also varied for BAN applications by connecting two Application layer transceivers and two Physical layer-based digital transceivers. The architecture is simulated in a Model-sim simulator. The complete Module is synthesized using different FPGA families, and the hardware design constraints are contrasted. The digital transceiver works at 231.28 MHz operating frequency, consumes 0.113W power, and provides a 7.7 Mbps data rate and 4.67 Kbps/Slice efficiency on Artix-7 FPGA. The proposed transceiver is also compared with existing digital transceivers with hardware constraints improvements.

Design of substrate integrated waveguide withMinkowski-Sierpinski fractal antenna for WBAN applications

This paper presents a new design of patch antenna using Minkowski-Sierpinski fractal technique with substrate integrated waveguide (SIW) to resonate at 60 GHz. The antenna is proposed to be used for wireless body area network applications (WBAN). The proposed antenna is implemented using Rogers 5880 substrate with permittivity of (εr) of 2.2 and loss tangent is 0.0004, height of the substrate is 0.381 mm. Computer simulation technology-Microwave Studio (CST-MW) is used to simulate the proposed antenna. The simulated results show a wide bandwidth of 3.5 GHz between the ranges of (58.3-61.7) GHz, with a good return loss of more than -10 dB. A simulated gain of 7.9 dB is achieved with a linear antenna efficiency of 91%. This proposed antenna is used to improve the quality of radiation pattern, bandwidth, and gain at millimetre wave (mm-Wave) band for WBAN applications.

A hybrid energy-efficient routing protocol for wireless body area networks using ultra-low-power transceivers for eHealth care systems

One of the major applications of Wireless Body Area Networks (WBANs), and the Internet of Things is the Electronic Health-Care systems. The progress in WBANs, and implanted health monitoring technologies have strong potential to alter the future of healthcare services by enabling ubiquitous monitoring of patients. An energy-efficient protocol is an important factor in the operation of eHealth care systems. A hybrid energy-efficient routing protocol is proposed in this paper for the distributed wireless body area network. In which a hybrid communication method and a new synchronization scheme are discussed. The hybrid communication enhances the network lifetime, and the synchronization scheme will consume less energy by avoiding collisions. The performance of the proposed protocol is analyzed, and it is compared with three baseline routing protocols at the 2.4 GHz ISM band with two ultra-low power transceivers.

Highly efficient artificial magnetic conductor enabled CPW fed compact antenna for BAN wearable applications

Abstract In this paper a coplanar waveguide feed (CPW) monopole antenna backed with artificial magnetic conductor (AMC) structure for efficient radiation has been presented for off-body wearable applications. A split ring resonator (SRR) having thiner and longer lines to produce higher inductance and six splits with smaller gaps for high capacitance have been placed underneath CPW fed monopole to achieve resonance mode at a lower frequency. Higher values of inductance and capacitance produce resonant modes at relatively lower frequencies resulting in highly miniaturized antenna. The desired −10dB S11 bandwidth has been optimized firstly, by tuning/optimizing flow of surface currents with the help of several slots/slits and later by realizing AMC reflector with the help of full ground backed foam. The proposed antenna covers 2.45 GHz industrial, scientific and medical (ISM) band body area network (BAN) application and posses good front to back ratio (FBR) and thereby low and acceptable values of specific absorption rate (SAR). The proposed antenna has been designed and simulated using Ansys high frequency structured simulator and tested using vector network analyzer and anechoic chamber. The simulated and measured results well agree with each other.

Low-power integrated transmitter design using frequency multiplication techniques

This paper proposes an approach to employ frequency multiplication techniques like edge-combining and third harmonic extraction in ultra-low-power integrated transmitter design. The overall power demand of the transmitter is reduced by keeping operating frequency of its components low. For that reason, edge-combining and third harmonic extraction are integrated directly into a switched mode power amplifier. Hence, the radio frequency signal is generated just before it is fed to the antenna. This leads to a reduced power demand of the overall transmitter in comparison to conventional designs where the oscillator and other components are operated directly at the radio frequency.Within this paper we propose an amplifier that generates a 2.4 GHz carrier frequency from a ring oscillator running at a low 200 MHz resulting in a frequency multiplication factor of twelve. The exemplary design is targeted to be used in ultra-low-power short range applications. Hence, our simulations using extracted layout models show that the amplifier provides an output power of approximately -12 dBm at a supply voltage of 0.6 V while consuming 2.4 mW of power fully integrated in a 180 nm 1P6M CMOS process.This demonstrates that the proposed techniques are especially suitable for ultra-low-power transmitter in short range applications. That includes medical and body area network applications.

Artificial Magnetic Conductor Based Miniaturized Frequency Re-configurable Dielectric Resonator Antenna for 5G and WBAN Applications

In this work a novel miniaturized frequency reconfigurable Dielectric Resonator antenna using Artificial Magnetic Conductor (AMC) surface is proposed. The prototype is set to work for 5G mid-band frequencies and Wireless Body Area Network (WBAN) applications. The work consists of two parts: firstly, the miniaturization of the prototype using AMC surface and secondly using the same AMC surface to reconfigure the frequency to another wireless application. Using AMC surface, the DR volume is reduced by 85% percent. Connecting the AMC unit cells through ideal switches (micro-trip slabs) re-configures the DR for different frequency. The overall performance observed before switching as well as after switching in both the cases is promising. The design is fabricated for performance analysis. A close agreement is reported between simulated and measured values of the reflection coefficients, radiation pattern, gain and efficiencies. The prototype has stable radiation pattern for both the operating frequencies. The impedance bandwidth values for both the resonance frequencies are 14.2% and 16% respectively. The prototype has a maximum gain of 6.8dBi and a maximum efficiency of 88%.

Design of CPW fed multiband antenna for wearable wireless body area network applications

This communication presents a multiband on-body conformal and wearable antenna for Wireless Body Area Network (WBAN) applications. The suggested wearable CPW-fed slot dipole antenna is incorporated with inductively coupled meander shape, T and O shaped resonators that lead to provide multiband operation. The resonant frequency is controlled by a definite resonant path, which leads to high degree of freedom in design paradigm. The proposed wearable antenna covers the 2.4 GHz/5.2 GHz/5.8 GHz WLAN, 3.5 GHz WiMAX, and 4.4 GHz C-bands and has an overall dimension of 60 × 40 × 0.254 mm3. The SAR analysis has also been presented for the antenna at several resonant frequencies which are well under the normal SAR criteria of 1.6 W/kg that suggests that the model performs satisfactorily for wearable applications. To characterize the performance of the antenna, the specimen of the antenna is rigorously tested in terms of antenna gain, S-parameters and flexibility under different bending configurations for radii values ranging from 90 to 30 mm. The reflection coefficient of the suggested antenna is also evaluated and the outcomes are compared under distinct on-body circumstances. Measured and simulated results of S11, radiation pattern and gain are in good agreement.

Design and analysis of low profile and low SAR full-textile UWB wearable antenna with metamaterial for WBAN applications

In this paper, a low-profile wearable antenna with metamaterial (MM) for wireless body area network (WBAN) applications is presented. The designed antenna with MM operates in the ultra-wideband (UWB) between 4.55 and 13 GHz and it has a thickness of 4.68 mm. To the best of our knowledge, it is the lowest thickness reported in the literature for UWB antennas with MM. The proposed is designed and manufactured using fully flexible textiles. The designed antenna was simulated in free space and on the human body model. Simulation results show that gain, directionality, and front-to-back ratio of the antenna increase considerably with the placement of the MM. Also, in simulations, it is found that the specific absorption rate (SAR) values for the designed antenna reduce by 98.3% when MM is used. These SAR values calculated for the designed antenna with MM are well below the limits defined in European standards. The designed antenna and metamaterials were manufactured, too, and scattering parameters were measured. Measurement results are in good agreement with the results found in the simulations. It shows that the proposed antenna is very suitable for use in WBAN applications due to its low thickness, having low SAR, and UWB operation.

Design and Modeling of Resource-constrained IoT based Body Area Networks

Due to the recent advancement and development of sensing, wireless, and communication technologies, therehas been a shift in attention towards Body Area Networks (BANs). One of the most important services of BAN is the remote monitoring of patients, enabling doctors to observe, diagnose, and prescribe the patients without being physically present. Various vital signs are being monitored by body sensing devices installed inside, on or off the body of patients, but most of these devices are constrained in terms of resources such as storage, processing, bandwidth, and energy due to their smaller size. This paper aims at highlighting the key findings related to BAN applications, constrained resources, and various resource management techniques. The paper also presents the design and modeling of a resource-constrained BAN system and discusses the various scenarios of BAN in the context of resource constraints. It further proposes an Advanced Edge Clustering (AEC) approach to manage the resources such as energy, storage, and processing of BAN devices while performing real-time data capture of critical health parameters and detection of abnormal patterns. The comparison of the AEC approach is done with the Stable Election Protocol (SEP) through simulations and empirical data analysis. The results show an improvement in energy, processing time and storage requirements for the processing of data on BAN devices in AEC as compared to SEP.

A Compact Highly Efficient Π-Section CRLH Antenna Loaded With Textile AMC for Wireless Body Area Network Applications

An ultrathin, compact, and highly efficient antenna based on the π-section composite right/left-handed (CRLH) methodology is presented. It operates at 2.45 GHz of the Industrial, Scientific and Medical (ISM) band with a physical size of 25 mm × 25 mm, a realized gain of 2.34 dBi, and a total efficiency of 87% in free space. Nevertheless, to maintain resonance at 2.45 GHz with body-loading scenarios, a high separation was required, leading to an overall large size. To circumvent that, an all-textile 2 × 2 artificial magnetic conductor (AMC) array was placed in-between the antenna and the human body. In free space, the low-profile integrated design exhibited a gain of 7.63 dBi (enhancement of 5.29 dBi) and total efficiency of 96.4%. The integrated design achieved a gain and total efficiency enhancements by 14.88 dBi and 72.4%, respectively, as well as, lower specific absorption rate (SAR) levels, in comparison with the CRLH antenna alone, for human loading cases. Results are achieved through circuit model and full-wave electromagnetic simulations. In addition, the CRLH antenna and AMC array structure were fabricated and measurements were undertaken, which agreed well with the simulated ones. Therefore, the integrated design is highly suggested to be recognized in wireless body area network (WBAN) and medical applications.

Printed compact asymmetric dual L‐strip fed split‐ring shaped EBG‐based textile antenna for WBAN applications

AbstractThis letter presents a design of very compact asymmetric dual L‐strip fed split‐ring shaped electromagnetic bandgap (EBG)‐based textile antenna for wireless body area networks (WBAN) applications, operating at frequency 2.45 GHz. The antenna radiator is composed of 2 × 1 array of EBG cells printed on same side of the substrate with partial ground plane to form a compact EBG surface, excited with a 50 Ω inverted L‐strip feed line. The partial ground plane with EBG cells is used to miniaturize the proposed antenna of size 40 × 20 × 0.3 mm3. The proposed compact asymmetric dual L‐strip fed wearable antenna (DLSWA) with EBG structure is fabricated on denim (jeans) substrate having dielectric constant (ɛr) 1.7 and thickness of 0.3 mm. The design of proposed antenna is optimized for Industrial, Scientific, and Medical (ISM) band (2.4‐2.48 GHz)through various parametric variations with simulated impedance bandwidth (BW) of 12.2% (2.3‐2.6 GHz) for reflection coefficient |S11| ≤ −10 dB and also exhibits stable radiation patterns with simulated peak realized gain of almost 3.5 dBi in the entire operational frequency band. The performance of proposed wearable antenna on human body is also studied and observed low specific absorption rate (SAR) value of 0.6 W/kg over 10 g of human tissues. The proposed compact asymmetric DLSWA is designed, fabricated, and tested. The simulated results of designed antenna are verified and validated with measured results which show good agreement for all radiation characteristics of proposed antenna for WBAN applications.