Body Area Network Applications Research Articles

Flexible low-profile shield for reducing back radiation of wrist-worn antenna

A flexible conducting lossy shield is developed and demonstrated for a reduction in the back radiation of a linearly polarized X-band patch antenna for Wireless Body Area Network (WBAN) applications. The proposed structure comprises a flexible patch antenna backed by a laminated sheet of Expanded Graphite (EG). This flexible sheet is prepared from EG powder pressed uniformly over a thin adhesive tape. The conducting nature of EG is exploited, and the EG sheet is used as a protective shield to prevent back radiation emanating out of the WBAN antenna from propagating toward the human body. The antenna performance is tested over human wrist phantoms experimentally and through full wave simulation studies. The results indicate the marginal variation in the −10 dB impedance bandwidth with a slight increase in the gain and directivity values for a resonant frequency in the range 9.7–10.3 GHz (bending radius variation of 40, 30, and 20 mm and along two bending planes). A measured on-body gain of 6.7 dBi is exhibited by the antenna backed by the EG shield and bent over a 20 mm radius human wrist phantom with an S11 of −19 dB, a −10 dB % bandwidth of 8%, and a directivity of 9.4 dBi. All the other bending configurations exhibit values higher than these. Electric field and Specific Absorption Rate (SAR) studies reveal a reduction in wave penetration by the EG shield antenna inside the wrist phantom with a decrease in the SAR by a maximum of 5%. The measured front-to-back ratio values indicate the lowering of back radiation with a maximum average increase of 76% exhibited by an EG backed antenna. The developed EG shield has an additional advantage of being a standalone structure, which can be integrated with any wearable antenna for a possible reduction in the back radiation.

Curvature-Adaptive Compact Triple-Band Metamaterial Uniplanar Compact Electromagnetic Bandgap-Based Printed Antenna for Wearable Wireless and Medical Body Area Network Applications

A novel, compact, monopole apple-shaped, triple-band metamaterial-printed wearable antenna backed by a uniplanar compact electromagnetic bandgap (UC-EBG) structure is introduced in this paper for wearable wireless and medical body area network (WBAN/MBAN) applications. A tri-band UC-EBG structure has been utilized as a ground plane to minimize the impact of antenna radiation on the human body and improve antenna performance for the proposed wearable antenna. Metamaterial triangular complementary split ring resonators (TCSRRs) are incorporated into the antenna and UC-EBG structure, resulting in a compact UC-EBG-backed antenna with an overall size of 39 × 39 × 2.84 mm3 (0.41 λg × 0.41 λg × 0.029 λg). The printed textile antenna operates at 2.45 GHz for the wireless local area network (WLAN), 3.5 GHz for 5G new radio (NR), and 5.8 GHz for the industrial, scientific, and medical (ISM) bands with improved gain and high-efficiency values. Furthermore, the performance of the antenna is analyzed on the human body, where three models of curved body parts are considered: a child’s arm (worst case) with a 40 mm radius, an adult’s arm with a 60 mm radius, and an adult’s leg with a 70 mm radius. The results demonstrate that the proposed antenna is an attractive candidate for wearable healthcare and fitness monitoring devices and other WBAN/MBAN applications due to its compact size, high performance, and low SAR values.

A Dual-Band Low SAR Microstrip Patch Antenna with Jean Substrate for WBAN Applications

This paper presents a low-profile dual-band microstrip patch antenna operated at the 2.45/5.8 GHz ISM bands, targeting wireless body area network (WBAN) applications. The proposed antenna is fabricated on a jean substrate measuring 74×82 mm2. The four corners of the conventional rectangular patch are cut to activate an additional operating frequency and to enhance the radiation pattern. The circular slot is added to the radiating patch to fine-tune the desired frequencies. The measured impedance bandwidth of the proposed antenna at 2.45 GHz and 5.8 GHz bands is 3.68% (2.40 GHz–2.49 GHz) and 3.81% (5.67 GHz–5.89 GHz), respectively. The measured maximum gains are 3.08 dBi at 2.45 GHz and 2.15 dBi at 5.8 GHz. Moreover, the antenna’s performance when placed on flat and rounded body surfaces is also investigated. The proposed antenna achieves stable radiation pattern and low specific absorption rate (SAR) value with low complexity in design. The results indicate that the proposed antenna can be a promising candidate for WBAN applications.

Implanted Rhombus Ring Partial Inset-Fed Circularly Polarized Microstrip Monopole Antenna for WBAN Applications

In the present article, a design approach to accomplish circular polarization-based rhombus ring microstrip-fed monopole antenna working at 5.8 GHz for wireless body area network (WBAN) applications is proposed. The input impedance calculation using an electromagnetic theory of transmission line in a travelling wave coupled to the parallel-plate inductor model is conducted. Radiated electric field pattern calculation of the conventional square ring microstrip patch antenna (MSPA) using Biot and Savart’s law is reported. The circular polarization of the proposed antenna is accomplished by loading the radiating path with a capacitive element sectioned in the neighbourhood of the feed line. The proposed planar monopole antenna of volume 0.38λ0×0.38λ0×0.029λ0 (λ0 is evaluated at the resonant frequency of 5.8 GHz) achieves a -10 dB impedance bandwidth of 86.20% in the band (3-8 GHz) with a stable real gain of 8.29 dBic in circular polarization at the resonant frequency of 5.8 GHz and axial ration bandwidth of about 32.75% in the (5-6.9 GHz) band. Specific absorption rate (SAR) evaluation of the studied antenna is computed numerically on a part of the human phantom model to justify its use in WBAN applications. It is noted that the maximum amount of radiation absorbed by a part of the human phantom model is limited to a maximum SAR value of 1.45 W/kg and 0.754 W/kg on 1 g and 10 g of tissue mass, respectively. The prospective design has been fabricated and tested, and the experimental results are in good agreement with the simulation outcomes.

SAR reduction of wearable SWB antenna using FSS for wireless body area network applications

SAR reduction of wearable SWB antenna using FSS for wireless body area network applications

Privacy-preserving intrusion detection in Internet of medical things neural networks using a novel recurrent U-Net auto-encoder algorithm for biomedical applications

The rapid development of Internet of Things (IoT) technology has enabled the emergence of the Internet of Medical Things (IoMT), especially in body area network applications. To protect sensitive medical data, it is essential to ensure privacy preservation and detect intrusions in this context. This study proposes a novel intrusion detection system that protects the privacy of IoMT networks, specifically in the context of body area networks. For feature extraction, the system employs a recurrent U-Net autoencoder algorithm, which effectively captures temporal dependencies in IoMT data. In addition, privacy is protected through the combination of data anonymization techniques and data classification using Principal Component Analysis (PCA). Combining the recurrent U-Net autoencoder algorithm, privacy preservation mechanisms, and PCA-based data classification, the proposed system architecture comprises the U-Net autoencoder algorithm. The proposed method is superior to existing approaches in terms of accuracy, precision, recall, F-measure, and classification loss, as demonstrated by experimental evaluations. This research contributes to the field of privacy protection and intrusion detection in IoMT, specifically in body area network applications.

All-Textile Compact Ultra-Wideband Microstrip Antenna with Full Ground Plane for WBAN Applications

A novel low-profile all-textile microstrip antenna for ultra-wideband (UWB) applications in wireless body area networks (WBANs) is presented. The antenna incorporates flexible materials such as felt and conductive fabrics which provide optimal wearing comfort and durability. The use of a single dielectric substrate layer facilitates the integration process. The antenna also features a full background plane that minimizes the back radiation towards the human body. Multiple branches are designed in a compact area to generate adjacent resonances, and their combination achieves broadband characteristics across the 4.83–9.57 GHz frequency band. The antenna has a miniaturized size of 60 mm × 60 mm, which is 1.6λg × 1.6λg (where λg represents the guided wavelength at the center frequency), and it has a high realized gain of up to 10 dBi. The fully grounded structure also ensures good isolation between the antenna and the human body, thereby alleviating concerns regarding safety and radiation degradation in WBAN context. Simulation results indicate that the antenna maintains high performance levels during various bending tests. Given its favourable properties like ultra-wide bandwidth, compact size, low profile, high flexibility, and low specific absorption rate (SAR), the proposed design could find broad application prospects in high-speed WBAN systems.

ENHANCING WEARABLE AND MEDICAL CONNECTIVITY: A NOVEL PRINTED TRIPLE-BAND METAMATERIAL ANTENNA FOR WBAN/MBAN APPLICATIONS

This paper presents a novel, compact, monopole apple-shaped, and triple-band metamaterial printed antenna for wireless body area network (WBAN) and medical body area network (MBAN) applications. The antenna is backed by a tri-band uniplanar compact electromagnetic bandgap (UC-EBG) structure that acts as a ground plane and incorporates metamaterial triangular complementary splitring resonators (TCSRRs). The proposed printed textile antenna operates at 2.45 GHz for wireless local area network (WLAN), 3.5 GHz for 5G new radio (NR), and 5.8 GHz for industrial, scientific, and medical bands. Implementing the UC-EBG structure resulted in a 99% decrease in the specific absorption rate (SAR) values over 1 g and 10 g of tissues and achieved gains of 5.45, 6.09, and 7.63 dBi at 2.45, 3.5, and 5.8 GHz, respectively. Due to its high performance, low SAR values, and compact size of 39 × 39 × 2.84 mm<sup>3</sup> (0.41 λ<sub>g</sub> × 0.41 λ<sub>g</sub> × 0.029 λ<sub>g</sub> ), the proposed antenna is an attractive candidate for wearable healthcare, fitness monitoring devices, and other WBAN/MBAN applications.

A Koch Fractal Octagonal Antenna with a Compact Design and Defected Ground Structure (DGS) for Ultra-Wideband (UWB) Wireless Usage.

This paper introduces a Koch fractal octagonal antenna designed for the Ultrawideband (UWB) Frequency range. The utilization of the Koch fractal in the antenna design contributes to size reduction as well as provides compactness in the antenna for UWB. Additionally, it has been noted that the Koch fractal offers wideband operation. The antenna employs copper as the conductor material, and Flame Retardant-4 (FR4) serves as the substrate. The substrate has a dielectric constant ϵr=4.4, a loss tangent tanδ=0.02, and a thickness (h) of 1.6 mm. The overall antenna’s dimensions are 34.3 × 26.5 × 1.6 or electrical dimensions represent as 0.68λ0 × 0.53λ0 × 0.032λ0 . It achieves a maximum gain of 8.94 dBi at a frequency of 12.25 GHz, offering a broad bandwidth ranging from 2 GHz to 12.1 GHz.This antenna exhibits resonance at three distinct frequencies, namely 3.3 GHz, 6 GHz, and 8.6 GHz, making it highly efficient with an overall efficiency of 96.8%. The time domain characteristic is acceptable for UWB, group delay is 1.1 ns, the The proposed antenna has a high-fidelity factor of 90.2, and the correlation coefficient is 0.9. which makes the antenna a good candidate for UWB. Due to its performance characteristics, this proposed antenna is well suited for short-range wireless personal area networks (WPANs), supporting high-data-rate applications like Bluetooth and wireless USB and Wireless Body Area Network (WBAN) applications. Its proficiency also extends to industrial settings, where it helps with precision in control systems, asset tracking, and short-range sensing and radar systems.

Effects Investigation of MAC and PHY Layer Parameters on the Performance of IEEE 802.15.6 CSMA/CA

The recently released IEEE 802.15.6 standard specifies several physical (PHY) layer and medium access control (MAC) layer protocols for variety of medical and non-medical applications of Wireless Body Area Networks (WBAN). The most suitable way for enhancing network performance is to be the choice of different MAC and PHY parameters based on quality of service (QoS) requirements of different applications. The impact of different MAC and PHY parameters on the network performance and the tradeoff relationship between the parameters are essential to overcome the limitations of exiting carrier sense multiple access with collision avoidance (CSMA/CA) scheme of IEEE 802.15.6 standard. To address this issue, we develop a Markov chain-based analytical model of IEEE 802.15.6 CSMA/CA for all user priorities (UPs) and apply this general model to different network scenarios to investigate the effects of the packet arrival rate, channel condition, payload size, access phase length, access mechanism and number of nodes on the performance parameters viz. reliability, normalized throughput, energy consumption and average access delay. Moreover, we conclude the effectiveness of different access phases, access mechanisms and user priorities of intra-WBAN.

Investigation of SAR reduction and gain enhancement using an all-textile antenna with metamaterial structure for wireless body area network applications

This work presents a wideband, low-profile, and flexible antenna that incorporates metamaterial (MTM) structures and textile materials. The antenna design is simulated using CST Microwave Studio, incorporating flexible textile elements such as a felt substrate and conductive fabric. The developed antenna's performance was examined numerically in free space and on a human body. The antenna with MTM technology operates in the ultra-wideband (UWB) with a bandwidth ranging from 3.86 to 13 GHz. It possesses a low profile with a thickness of 5.34 mm, making it suitable for applications in wireless body area networks (WBAN). Through the integration of metamaterial structures, the antenna's gain is enhanced, reaching 8.85 dBi compared to the initial gain of 5.34 dBi. Notably, the gain consistently exceeds 6 dBi across the entire UWB range, indicating focused power in a specific direction. For applications on the human body, specific absorption rate (SAR) values were calculated and found to be well within safety limits defined by European standards. This ensures minimal back radiation when the antenna is worn on the body, enhancing signal transmission range in WBAN applications.

Comprehensive review of the human body communication system for wireless body area network applications

Comprehensive review of the human body communication system for wireless body area network applications

Design of a compact sigma slotted dual-mode UWB antenna for wireless body area network applications

Abstract This article presents the design of a novel sigma slotted circular monopole antenna for wireless body area network applications. The design is proceeded with a sigma-shaped slot etched on the circular radiator with Rogers 4003C substrate. The size of the proposed antenna is 30 × 30 × 1 mm3. With partial ground plane, the bandwidth characteristics of the antenna have been enhanced. The designed antenna covers 2–10 GHz of the ultra wideband, thereby providing more than 106% bandwidth. The antenna exhibits high gain values of 1.95, 3.23, 3.46, and 5.95 dB at 2.45, 3.45, 5.8, and 9.5 GHz, respectively. The proposed design operates on off-body mode at 2.45 GHz and on-body mode at 5.8 GHz, thus acting as a dual-mode antenna. To ensure the health and safety measure, specific absorption rate analysis was done for both low and high values of input power and also with Cartesian and cylindrical human arm models. Bending analysis was also done. The time domain parameter group delay was also analyzed for the proposed antenna for on- and off-body scenarios. The prototype was fabricated, and validation of simulation results was done for free space and on-body scenarios.

Improved wearable, breathable, triple‐band electromagnetic bandgap‐loaded fractal antenna for wireless body area network applications

AbstractA compact triple‐band porous electromagnetic bandgap structure‐loaded coplanar‐waveguide‐fed wearable antenna is introduced for applications of wireless body area networks. The porous structure is aimed to create a stopband or bandgap in the electromagnetic spectrum and increase breathability. The holes in the bottom electromagnetic bandgap surface increase the inductance, which in turn increases the bandwidth. The final design resonates at three bands with impedance bandwidths of 264 MHz, 100 MHz, and 153 MHz and maximum gains of 2.18 dBi, 6.75 dBi, and 9.50 dBi at 2.45 GHz, 3.5 GHz, and 5.5 GHz, respectively. In addition, measurements indicate that the proposed design can be deformed up to certain curvature and withstand human tissue loading. Moreover, the specific absorption rate remains within safe levels for humans. Therefore, the proposed antenna can suitably operate in the industrial, scientific, and medical, Bluetooth, Wi‐Fi, and WiMAX bands for potential application to wireless body area networks.

Compact eight-shaped ISM-I band wearable antenna for wireless body area network applications

Abstract The design and analysis of the electrically small eight-shaped wearable antenna for both on- and off-body communication is proposed in this paper. An eight-shaped radiating structure is placed over the jeans substrate and an I-shaped slot is introduced in the ground plane which makes the antenna resonates at the ISM-I band (2.4 GHz). The antenna has a compact size of 0.30λ 0 × 0.20λ 0 × 0.001λ 0, where λ 0 is the free space wavelength at the resonance frequency. The impedance bandwidth (≤−10 dB) of the antenna is 6.1 % and 5.8 % in free space and presence of a human body phantom respectively. The antenna design exhibits good gain along with an improved omnidirectional radiation pattern. The specific absorption rate (SAR) of the antenna averaged over 1 g of tissue is 0.21 W/kg at 2.45 GHz which is far below the FCC standard. The paper also discusses the bending analysis and the fundamental size limitations of the small antenna, concluding that it is suitable for practical use. The simulated results of the prototype are validated by the measured results.

Compact Ultra-­Wideband Planar Inverted F Antenna on Laminated Paper­-Based Substrate with Reduced Specific Absorption Rate

This paper presents a laminated paper-based Planar Inverted F Antenna (PIFA) for wireless body area network (WBAN) applications. The major challenges like providing adequate thickness, uniformity of surface, and water wet ability associated with paper substrate have been transcended in this antenna design by laminating the substrate with a transparent sheet. The simulated and measured reflection coefficients of the fabricated antenna in free space and on human arm are remarkably good, validating the prototype’s utility. It can operate effectively in GSM, WMTS, GPS, DCS, ISM, WiMAX, HIPERLAN, WLAN, and UWB frequency bands with S11 less than -10 dB and the gain ranging from 0.94 to 9.53 dB (free space) and 1.03 to 6.07 dB (on-body). The electrical size of the proposed antenna is 0.16 λg x 0.12 λg at 0.7 GHz with a group delay below 2.3 ns over the desired frequency bands. The performance characteristics are also investigated on-body and it encompasses most of the desired frequency bands for the body area network. This paper also analyses the specific absorption rate (SAR) of the designed antenna by placing it on a tissue-layered human arm model, which is 0.64 Watt/kg, complying with the SAR safety guidelines.

Textile and metasurface integrated wide-band wearable antenna for wireless body area network applications

Wireless Body Area Network (WBAN) enhances the quality of life through personal health and remote healthcare monitoring. In this work, we present a numerical model, which is based on CST Microwave Studio simulations, and a fabrication process to achieve a wideband, low-profile, and flexible wearable antenna by integrating textiles with a metasurface (MTS). The performance of the developed antenna was investigated in free space and on a human body (chest, arm, and leg) both numerically and experimentally. The results showed that by incorporating a metasurface structure on the antenna, the simulated gain was improved from 6.1 dBi to 9.08 dBi, while the measured gain was increased from 6.63 dBi to 8.49 dBi. The increased gain in a specific direction is related to more power concentration in that direction. The antenna operates in a bandwidth ranging from 6 to 12 GHz, which is preferred for WBAN applications. The antenna with an MTS structure displayed a more uniform radiation pattern with greater directivity and a Front-to-Back Ratio (FBR) of approximately 15 dB from both numerical and measured results, which is essential for WBAN to avoid back radiation from the body while worn and to increase the wireless signal distance. Additionally, numerical analysis of the bending evaluation for different diameters revealed that its reflection coefficient is not much altered. We believe that the developed structure could assist in the fabrication of unique WBANs and healthcare monitoring devices.

Ultra-wideband CMOS power amplifier for wireless body area network applications: a review

<span lang="EN-US">A survey on ultra-wideband complementary metal-oxide semiconductor (CMOS) power amplifiers for wireless body area network (WBAN) applications is presented in this paper. Formidable growth in the CMOS integrated circuits technology enhances the development in biomedical manufacture. WBAN is a promising mechanism that collects essential data from wearable sensors connected to the network and transmitted it wirelessly to a central patient monitoring station. The ultra-wideband (UWB) technology exploits the frequency band from 3.1 to 10.6 GHz and provides no interference to other communication systems, low power consumption, low-radiated power, and high data rate. These features permit it to be compatible with medical applications. The demand target is to have one transceiver integrated circuit (IC) for WBAN applications, consequently, UWB is utilized to decrease the hardware complexity. The power amplifier (PA) is the common electronic device that employing in the UWB transmitter to boost the input power to the desired output power and then feed it to the antenna of the transmitter. The advance in the design and implementation of ultra-wideband CMOS power amplifiers enhances the performance of the UWB-transceivers for WBAN applications. A review of recently published CMOS PA designs is reported in this paper with comparison tables listing wideband power amplifiers' performance.</span>

Mutual coupling reduction in a textile ultra-wide band MIMO antenna

This paper presents a mutual coupling reduction technique in a textile ultra-wideband (UWB) multiple-input–multiple-output (MIMO) antenna system implemented on a textile substrate. The compact textile UWB MIMO antenna consists of two patch antennas implemented on a felt textile substrate. The compact size and close placement of the antennas in a MIMO system cause higher mutual coupling which deteriorates the performance of the communication systems. To minimize the mutual coupling, Parasitic Elements and Defected Ground Structures are used in the designed textile UWB MIMO antenna. The MIMO antenna performed very well over almost the whole UWB frequencies ranging from 3.29 GHz to 13.3 GHz. The simulated and the measured parameters showed a good impedance matching with an impedance bandwidth of 133.4%. The results showed an improvement of 20 dB isolation at certain frequencies without impacting the reflection coefficient S11 and the antenna impedance bandwidth. The MIMO antenna has good diversity performance parameters in terms of Envelope Correlation Coefficient (ECC), Diversity Gain, Mean Effective Gain (MEG) and radiation pattern and the results indicate that the textile antenna is suitable for UWB MIMO applications. The overall size of the antenna is 30x60 mm2. Fully embroidered structure provides freedom of movement and comfort, so it is a good fit for Wireless Body Area Network applications.

Compact hybrid EBG microstrip antenna for wearable applications

Abstract A novel strip line fed, circularly polarized (CP), annular slotted dual band antenna using hybrid electromagnetic band gap (EBG) structure for Global Positioning System (GPS) has been herein designed, analyzed, and investigated for wearable applications. Adjusting the radii of the annular slots on the radiating patch excellent circular polarized (CP) radiation and impedance matching is achieved. The design demonstrates Kapton based flexible, robust, and low-profile solution with permittivity of 3.4 to meet the requirements of wearable applications. Due to the high losses of the animal body, the electromagnetic band gap (EBG) structure is used to reduce back radiation and the effect of frequency detuning. The proposed antenna structure also enhances the front-to-back ratio (FBR) by 10 dB. This antenna with dimensions 0.56λ 0 × 0.4913λ 0 × 0.002λ 0 analyzed using a flexible Kapton substrate. Optimized hybrid EBG structure provides an excellent Specific Absorption Rate (SAR) along with all other antenna parameters, within acceptable for GPS-based wearable applications at 1.13 GHz and 1.157 GHz frequency band. Therefore the proposed antenna is a suitable candidate for GPS-based tracking and wireless body area network (WBAN) applications. The proposed antenna was also tested upon fabrication and the measured results agree with simulated results.