Human Body Radiation Research Articles

Simulation and Design of Three 5G Antennas

In the context of 5G networks, this paper investigates microstrip array antennas and mobile terminal MIMO array antennas. It introduces two innovative designs and, based on these, develops and fabricates a mobile terminal antenna. The first of these designs, a 4 × 4 microstrip array antenna operating in the LTE band 42 (3.4–3.6 GHz), is researched and fabricated and an innovative approach, combining embedded and coaxial feeding methods, is proposed and employed. Measurement results indicate a bandwidth of 373 MHz (3.321–3.694 GHz), achieving a relative bandwidth of 10.7%. The antenna exhibits a high gain of 12.7 dBi, with an undistorted radiation pattern, demonstrating excellent directional characteristics. The second of these designs, a “loop-slot” MIMO antenna designed for 5G mobile devices with metal frames, is investigated. By opening slots in the metal frame and integrating them into the antenna’s feeding structure, the decoupling principle is analyzed from the perspective of characteristic mode theory. This design shares resonant modes between the loop and slot antennas, allowing for the overlapping placement of the two antenna units. Experimental results confirm an isolation level exceeding 21 dB, with significantly reduced dimensions. Finally, an eight-unit MIMO antenna is designed and fabricated for 5G mobile devices with metal frames. Continuous optimization of the “loop-slot” module layout and unit spacing leads to a compact and miniaturized antenna structure. Measurement results show an isolation level exceeding 17 dB, radiation efficiency ranging from 65.8% to 73.7%, and an envelope correlation coefficient (ECC) below 0.03. Finally, an analysis of specific absorption rate (SAR) demonstrates excellent MIMO performance in terms of human body radiation exposure.

Molecular‐Engineered Wool for Sustainable All‐Weather Radiative Cooling Textiles

AbstractPersonal thermal regulation through passive radiative cooling is an effective strategy to achieve sustainable development. Although recent advances have introduced various cooling textile designs, the extensive use of materials unsuitable for common textiles, alongside coating or compositing technologies, not only compromises the wearability and safety of these textiles but also impacts green sustainability. Herein, it is shown that wool is a promising natural material for transferring mid‐infrared human body radiation, but the high absorption in the solar spectrum prohibits wool from achieving satisfactory daytime radiative cooling. Thus the natural wool impregnates zinc ions into the protein chains to form a zinc‐ion woolen (wool‐Zn) fabric. The wool‐Zn fabric can provide humans with a cooling sensation both indoors and daytime outdoors, showing a temperature reduction of 2 °C on human skin indoors and a reduction of 7 °C on artificial skin under direct sunlight, respectively, when covered by wool‐Zn fabrics compared to when covered with cotton. Moreover, the wool‐Zn fabric shows desirable antibacterial properties and durability against washing and abrasion, while maintaining desirable wearability. As a result, the wool‐Zn fabric shows great potential for commercial application in personal thermoregulation and provides an effective avenue toward sustainable energy and environment.

AUTOMATED DETECTION OF CHILDHOOD OBESITY IN ABDOMINOPELVIC REGION USING THERMAL IMAGING BASED ON DEEP LEARNING TECHNIQUES

Childhood obesity is a preventable disorder which can reduce the risk of the comorbidities linked with an adult obesity. In order to improve the lifestyle of the obese children, early and accurate detection is required by using some non-invasive technique. Thermal imaging helps in evaluation of childhood obesity without injecting any form of harmful radiation in human body. The goal of this proposed research is to evaluate the body surface temperature in abdominopelvic and cervical regions and to evaluate which region is best for predicting childhood obesity using thermal imaging. Next, to customize the ResNet-18 and VGG-19 architecture using transfer learning approach and to obtain the best modified classifier and to study the classification accuracy between normal and obese children. The two-study region which was selected for this study was abdominopelvic and cervical region where the mean skin surface temperature was recorded. From the two selected body regions, abdominopelvic region has depicted highest temperature difference of 10.98% between normal and obese subjects. The proposed modified ResNet-18 model produced an overall accuracy of 94.2% than the modified VGG-19 model (86.5%) for the classification of obese and normal children. Thus, this study can be considered as a non-invasive and cost-effective way for pre-screening the obesity condition in children.

Human body radiation area factors for diverse adult population.

Radiation accounts for a significant fraction of the human body and environment heat exchange and strongly impacts thermal comfort and safety. The direct radiative exchange between an individual and a source or sink can be quantified using the effective (feff) and projected radiation area factors (fp). However, these factors have not been quantified for half of the population of the USA with an above-average body mass index (BMI). Here, we address this gap by developing thirty male and thirty female computational manikin models that cover the 1 to 99 percentile variation in height and BMI of adults in the USA. The radiative simulations reveal that the feff and the fp angular distributions are nearly independent of gender, height, and BMI. Appreciable relative differences from the average models only emerge for manikins with BMI above 80th percentile. However, these differences only occur at low zenith angles and, in absolute terms, are small as compared to variations induced by, for example, the zenith angle increase. We also use the manikin set to evaluate whether the body shape impacts the quality of human representation with several levels of geometrical simplification. We find that the "box/peg" body representation, which is based on the hemispherical fp average, is independent of the body shape. In turn, the fp distributions averaged over the azimuth angle range, representing the rotationally symmetric humans, are only impacted to the same degree as for the anatomical manikins. We also show that the anatomical manikins can be closely approximated by the multi-cylinder and sphere representation, at least from a radiation perspective. The developed anatomical manikin set is freely available and can be used to compute how body shape impacts a variety of external heat transport processes.

Inorganic additive-incorporated composites with infrared radiation performance for thermal management

PurposePersonal thermal management in functional textiles is in increasing demand for health care, outdoor activity and energy saving. Thus, developing new strategies is highly desired for radiative cooling and/or heating by manipulation of the transmissivity, reflectivity and absorptivity of the textiles within solar energy and human body heat radiation ranges.Design/methodology/approachInorganic additives including TiO2, Fe2O3, carbon black (CB), graphene and mica were incorporated into polymer films. The inorganic additives' full spectrum properties and thermal responses were comprehensively investigated.FindingsThe CB composite film showed the highest absorptivity over the full solar to human body radiation spectrum. The mica-white (mica-w) (mica coated with TiO2) and mica-red (mica-r) (mica coated with Fe2O3) composites showed the lowest solar energy absorptivity and a strong body heat radiation reflectivity. Furthermore, according to composites' thermal responses to the simulated solar and human body radiations, CB and mica are promising for both cooling and heating when applied in dual-functional thermal management textiles.Research limitations/implicationsResearch has limitation related the amount of additives which can be added to textile. When powder is added to polyester yarn, the amount is limited by 2–3%. When powder is added to the composite which is used for printing, the amount of powder is limited by 5%.Practical implicationsA lot of apparel, especially sport apparel, contains prints. Decoration is one part of print application. Now, a lot of companies work under development of different additives, which provide additional properties to apparel. The closest targets for powder added to prints are cooling and heat retention. Quite often, inorganic additives possess dual properties: the inorganic additives may be heat reflective which his needed for heat retention, but may have high-thermal conductivity, which works well for cooling. Human body has complicated mechanism of heat exchange: convection, radiation and moisture evaporations play main role. The same additive may be cooling if there is a contact with skin but may be heating (IR reflective) if placed in the second or third layer. Thus, effect is needed to be studied first before real application.Originality/valueThis work could provide a comprehensive guideline for the rational design and application of thermal management composite textile materials by revealing the full solar to human body radiation performance of a series of inorganic materials.

Multifunctional Textiles Enabled by Simultaneous Interaction with Infrared and Microwave Electromagnetic Waves

AbstractConventional textiles keep the body warm and provide an aesthetic appearance for human beings, while they are insufficient for military and civil applications in harsh environments. Multifunctional textiles that are capable of creating infrared (IR) camouflage, electromagnetic interference (EMI) shielding, and personal warming by interacting with both IR and microwave electromagnetic waves (EMWs) are developed. The inorganic–organic polytetrafluoroethylene (PTFE)/Ag/PTFE (IO‐PAP) building blocks are deposited on the polyurethane (PU)‐coated textiles using an eco‐friendly magnetron sputtering technique, where a smooth and durable Ag layer is grown, circumventing the large roughness and less connection between fibers in conventional textiles. Using the IO‐PAP building blocks, the ultralow IR emissivity and the ultrahigh microwave reflectance are achieved for effective IR camouflage and EMI shielding, respectively, together with satisfactory mechanical robustness. The EMI shielding effectiveness is further improved to 73 dB through employing a Fabry–Pérot‐based double‐sided PAP (D‐PAP) architecture. The D‐PAP‐coated textiles also exhibit personal warming, increasing the skin temperature by 2.7 °C compared with conventional cotton through reflecting thermal radiation of human bodies and mitigating radiative heat loss from textiles. This work will inspire the ultra‐band EMW engineering of textiles for realizing advanced functionalities in a way of eco‐friendly and scalable manufacture.

A Personal Thermal Management Janus Textile with Solar Energy and Human Body Radiation Energy Heating

A Personal Thermal Management Janus Textile with Solar Energy and Human Body Radiation Energy Heating

Electromagnetic Waves Absorption Experiment on A Human Body with 2.45 GHz Directional Antenna

Micro-doppler radar is a technique that is also possible for medical applications, such as breath and heartbeat detection. These potential applications are coming from wave detection, which is reflected by an object under test. In an ideal environment like in an anechoic chamber room, the emitted radiation suffers from some losses, including path loss and object absorption. These losses reduce the detected power and later influence the accepted signal quality and accurate prediction. Among various loss factors, this paper presents human body radiation absorption by emitting electromagnetic waves at a frequency of 2.45 GHz of a directional horn antenna. In every experiment uses one type of antenna for transmitting and receiving radiation. The antenna is connected to a USRP software-defined radio module and then connected to a computer to obtain experimental data. The result shows that the absorption level of a human body detected by using the horn antenna is 11.07 dB. This information is useful to predict a reasonable power and distance that can be covered by a detection system by applying the micro doppler radar principle.

A novel UWB microstrip patch antenna des for cardio activity monitoring application

Nowadays health care diagnostic applications are preferring microstrip type of antennas effectively. The market for noninvasive and contactless physiological function measurement is growing all the time, and such equipment is useful for tracking the conditions of hospitalized patients. This paper proposes a novel Ultra wideband microstrip patch antenna design that can be used for cardio activity monitoring. Ultrawideband antennas are increasingly being used in short-distance communication links because they can relay a large amount of data over a broad frequency spectrum. It poses little danger to the human body, consumes little power, and is totally compatible with peripheral devices. It has a low chance of human body radiation, as well as low power consumption and high compliance with peripheral devices. As a result, UWB antennas have been regarded as a useful piece of technology for calculating biological data. As signals travel through ultra-wide band antennasover a large frequency spectrum of small signals, less power is needed, and as a result, low noise is tolerated. The suggested microstrip patch antenna is made of FR-4 (Flame Resistant-4) substrate material and resonates at 2.5 to 4.5 GHz. The proposed antenna's simulated VSWR, S-parameters, and radiation pattern have been studied.

Passive Detection and Imaging of Human Body Radiation Using an Uncooled Field-Effect Transistor-Based THz Detector.

This work presents, to our knowledge, the first completely passive imaging with human-body-emitted radiation in the lower THz frequency range using a broadband uncooled detector. The sensor consists of a Si CMOS field-effect transistor with an integrated log-spiral THz antenna. This THz sensor was measured to exhibit a rather flat responsivity over the 0.1–1.5-THz frequency range, with values of the optical responsivity and noise-equivalent power of around 40 mA/W and 42 pW/, respectively. These values are in good agreement with simulations which suggest an even broader flat responsivity range exceeding 2.0 THz. The successful imaging demonstrates the impressive thermal sensitivity which can be achieved with such a sensor. Recording of a 2.3 × 7.5-cm-sized image of the fingers of a hand with a pixel size of 1 mm at a scanning speed of 1 mm/s leads to a signal-to-noise ratio of 2 and a noise-equivalent temperature difference of 4.4 K. This approach shows a new sensing approach with field-effect transistors as THz detectors which are usually used for active THz detection.

Electromagnetic radiation of human body before and after intense exercise

<span>This paper investigates the electromagnetic radiation (EMR) of the human body before and after intense exercise. The intensity of exercise refers to the rate or the effort at which the activity is being performed. 30 healthy students participated in this research. The data were collected at the specific point of the human body by using a frequency detector. The reading of the frequency was taken 5 times at each point at the same location; hence, the average value is calculated for data analysis. This frequency measurement is recorded two times which is before and after intense exercise with a consistence protocol for all participants. The collected data is analyzed by using MATLAB programming tool which converts the data frequency into 15 colours of bio-energies which symbolizes different energy field score. The score represents the health level of the samples at specific point. From the analysis, higher frequency of EMR is detected after intense exercise compared to before intense exercise. There is also a significant change in the physical health score categories. This indicates that the intense exercise influences the body EMR radiation frequencies.</span>

Multiscale Disordered Porous Fibers for Self-Sensing and Self-Cooling Integrated Smart Sportswear.

Smart clothing has demonstrated potential applications in a wide range of wearable fields for human body monitoring and self-adaption. However, current wearable sensors often suffer from not seamlessly integrating with normal clothing, restricting sensing ability, and a negative wearing experience. Here, integrated smart clothing is fabricated by employing multiscale disordered porous elastic fibers as sensing units, which show the capability of inherently autonomous self-sensing (i.e., strain and temperature sensing) and self-cooling. The multiscale disordered porous structure of the fibers contributes to the high transparency of mid-infrared human body radiation and backscatter of visible light, which allows the microenvironment temperature between the skin and clothing to drop at least ∼2.5 °C compared with cotton fabrics. After the capillary-assisted adsorption of graphene inks, the modified porous fibers could also possess real-time strain and temperature-sensing capacities with a high gauge factor and thermal coefficient of resistance. As a proof of concept, the integrated smart sportswear achieved the measuring of body temperature, the tracking of large-scale limb movements, and the collection of subtle human physiological signals, along with the intrinsic self-cooling ability.

FDTD and Empirical Exploration of Human Body and UWB Radiation Interaction on TOF Ranging

In time-of-flight (TOF)-based human ranging systems, target sensors are often mounted on or close to the human body, which may raise non-line-of-sight (NLOS) cases and lead to significant ranging errors depending on the relative position between the body, transmitter (Tx), and receiver (Rx). In recent years, ultrawideband (UWB) has become a very popular technology for human TOF ranging, but its human body interactions have not been studied yet extensively. In this letter, the UWB and human body interaction is explored by the finite-difference time-domain (FDTD) technique, and the obtained E-field strength variation results are validated by means of commercially available UWB kits. Additionally, an UWB-ranging error model with respect to the human body shadowing effect is proposed and evaluated by extensive measurements, i.e., in indoor environments, line-of-sight (LOS) and NLOS are found to be well modeled by Gaussian and Gamma distributions, respectively, while in outdoor fields, LOS and NLOS are both modeled by Gaussian distributions. The main conclusion of this study is that there is a clear pattern between a gain in the E-field strength and TOF ranging errors. It can be established that in a worst-case scenario, a gain of 4–18 dB is observed, which corresponds to about 30–60 cm of TOF ranging errors.

Human body exergy consumption models’ evaluation and their sensitivities towards different environmental conditions

We can use the concept of exergy to analyze a human body as a heat emitter: while generating heat continuously, the body remains at roughly the same temperature through physiological responses such as shivering, sweating, breathing thus raising/decreasing the core and/or skin temperature to maintain effective heat dissipation. Existing literature provides an estimated exergy consumption rate of the human body ranging from 2 to 5W/m2, while nearly unanimously agreeing on a local exergy consumption minima points to potential individual thermal comfort. To clarify the underlying assumptions used in the existing human body exergy models, we analytically and numerically reviewed the terms used for assessing metabolism, radiation, evaporation, and convection exergy changes of the human body in this paper. We observed overestimations of exergy from metabolism, underestimations of exergy change through radiation, and some caveats in the signage of convective exergy losses in the results we obtained. We were also able to propose an improved expression to estimate human body radiation exergy exchanges as well as selecting reference temperatures that are more process-specific. Future studies that provide experimental verification of these models were also deemed necessary.

Temperature Regulation in Colored Infrared-Transparent Polyethylene Textiles

Summary Effectively regulating heat flow between the human body and its environment not only increases thermal comfort but also presents a novel and potentially cost-effective approach to reducing building energy consumption. Infrared property-engineered textiles have been shown to passively regulate radiative heat dissipation for effective cooling and warming of the human body. However, a lack of dyes that can tune the textile color without compromising the infrared properties remains a major impediment to textile commercialization. Here, we report a new strategy utilizing inorganic nanoparticles as a coloring component for scalable brightly colored, infrared-transparent textiles. The as-fabricated composite textiles not only show a high infrared transparency of ∼80% and a passive cooling effect of ∼1.6°C–1.8°C but also exhibit intense visible colors with good stability against washing. This facile coloration approach will promote the commercialization of radiative cooling textiles in temperature-regulating wearable applications for effective energy savings.

Multispectral pedestrian detection based on deep convolutional neural networks

Vision-based pedestrian detection that can last all day is crucial in advanced driver-assistance systems (ADAS), autonomous vehicles and video surveillance. Based on the fact that the wavelength of human body radiation falls around 9.3 μm, thermal images have distinctive advantages for pedestrian detection in the nighttime. With the recent success of convolutional neural networks (CNNs) in the vision community, how to properly explore information in color and thermal images using CNNs-based methods attracts the attention of researchers. Previous CNN-based multispectral pedestrian detectors focus on the design of network architectures. The main contributions of this paper are as follows. First, pixel-level image fusion are also extensively evaluated based on a state-of-the-art CNNs-based framework in the daytime and nighttime for pedestrian detection. Second, the effective strategies to combine pixel-level fusion methods and CNN-fusion architectures are studied based on extensive experimental results. Two combination strategies are designed and an exhaustive experimental analysis is performed to evaluate different combinations for all-day pedestrian detection. Extensive results based on a multispectral pedestrian benchmark show that some pixel-level image fusion methods can achieve similar or even better performance than CNN-fusion architectures, which emphasizes the importance of pixel-level fusion in CNN-based pedestrian detectors. The combination of both can usually more properly exploit multispectral information and further boost detection performance.

(Keynote) Ferroelectric Polymers for Flexible Electronics

Ferroelectric polymers from the PVDF-family have proven to be multifunctional and self-sustaining materials with a broad deployment in printed and flexible electronics. They can be used in large and flexible form factors for detecting mechanical excitations such as pressure variations, force touch and impact, for sensing human-body radiation and proximity, as vibration sensors for structure-borne sound detection and acoustics, as fast and high-precise strain sensors, as stretchable vital parameter sensors for movement, ECG and respiratory rate monitoring, as well as piezoelectric energy harvesting elements, just to name a few. This talk will provide an overview of the most attractive applications of PVDF-based devices such as pressure-sensitive human-machine interfaces on planar, flexible and 3D-shaped surfaces (also in combination with flexible displays), large-area impact sensing films for material and crash testing, sensors for structural health monitoring, ultrathin microphones smoothly integrated on versatile, arbitrary shaped object surfaces, smart skin patches for vital monitoring and intelligent floor for smart home applications and energy supply for low-power sensor networks. The sensors are entirely fabricated by screen printing which is one of the most common techniques used in printed electronics for the fabrication of large-area flexible components and multifunctional devices. Screen printing is highly tolerant to the type and form factor of substrates, the rheology of ink materials, provides sufficient alignment accuracy for multilayer printing and can be done in a sheet-to-sheet or roll-to-roll scheme. The printed ferroelectric polymer sensors come in two versions; (i) either they have a sandwich-type structure of four layers that are printed onto a flexible or stretchable substrate (e. g. plastic films, paper, and textiles up to A3) and response accurately, fast and reproducibly to pressure and temperature changes over large dynamic ranges or (ii) a two layer structure that is highly sensitive to lateral strain and vibrations. By optimizing the design, the printing and annealing process as well as the poling conditions and the source material, functional sensors with a soft yield of more than 98% with less than ± 5% deviation in the remnant polarization were demonstrated. It is also interesting to note that extended aging tests under definite climate and shock conditions revealed more than 98% preservation of the remnant polarization for high molecular weight PVDF-TrFE polymers. Based on these sensors applications such as flexible 3D user interfaces [1,2] (Fig. 1) and large-area force, impact and proximity sensors, ultrathin object-integrated microphones as well as medical patches will be presented either in a passive-matrix or an active-matrix ferroelectric sensor configuration with OTFT- or OECT-backplane. Finally, a novel printable nanocomposite material, which allows reducing the cross-sensitivity between the pyro- and piezoelectric sensing modes, will be presented. This material is composed of inorganic ferroelectric nanoparticles blended in a ferroelectric polymer matrix. By exploiting the fact that the piezoelectric coefficient in inorganic ceramics has an opposite sign to that one of the ferroelectric polymer either the piezo- or the pyroelectric activity can be suppressed by independently defining the poling direction of particles and matrix in a clever poling procedure [3]. M. Zirkl, A. Sawatdee, U. Helbig, M. Krause, P. Bodö, P. Andersson Ersman, D. Platt, S. Bauer, G. Domann, and B. Stadlober, Adv. Mat. 23, 2069 (2011)C. Rendl, D. Kim, P. Parzer, S. Fanello, M. Zirkl, G. Scheipl, M. Haller, S. Izadi, FlexCase: Enhancing Mobile Interaction with a Flexible Sensing and Display Cover, Proceedings of the 2016 CHI Conference on Human Factors in Computing Systems, San Jose, California, USA, pp. 5138-5150, doi: 10.1145/2858036.2858314 (2016)I. Graz, M. Krause, S. Bauer-Gogonea, S. Bauer, S. P. Lacour, B. Ploss, M. Zirkl, B. Stadlober, and S. Wagner, J. Appl. Phys. 106, p. 034503 (2009) Figure 1

Electret nanofibrous membrane with enhanced filtration performance and wearing comfortability for face mask

Airborne particulate matter (PM) pollution has become a serious threat to human health, thus it is highly desired for a high-filtration-performance and good-wearing-comfort face mask. Herein, a highly breathable and thermal comfort filter medium consisting of electret polyethersulfone/barium titanate nanofibrous membrane (PES/BaTiO3 NFM) integrated on a nonwoven polypropylene substrate was developed. Benefiting from the high porosity and optimized injection charge energy, the PES/BaTiO3 membrane was endowed with a good air permeability of 743 mm s−1, a modest water vapor permeability of 6.24 kg m−2 d−1, and an enhanced charge storage stability. In addition, the electret PES/BaTiO3 NFM1.5 medium with a low basis weight of 4.32 g m−2 still shows a high filtration efficiency of 99.99% and a low pressure drop of 67 Pa after being treated at 200 °C for 45 min, which is better than that of commercial media. Moreover, 3D simulation based on the characters of composite membrane was processed to graphically express the airflow distribution during the filtration process. Significantly, the NFM1.5 with a high infrared (IR) transmittance of 93.4% led to an effective radiative cooling to human body radiation. This multifunctional fibrous medium design may provide new insights into the development of environmental adaptive protection materials.

Electromagnetic Radiation (EMR) of Human Body Before and After Jogging

<p class="Abstract">The research is on the electromagnetic radiation of human body before and after jogging. 30 healthy students from UiTM with an age range of 23-25 years old volunteered. The seven locations of chakra points were measured. The body frequency (in MHz) is captured using frequency detector by taking the reading of the frequency 5 times at each point at the same location; hence, the average value is calculated for data analysis. This frequency measurement is recorded two times which is before and after jogging with a consistence protocol for all participants. The data in terms of frequency (Hertz) is converted into 15 colours of bio-energies representing the health level. The finding shows that 63.3% of participants’ health level improved after jogging. While 33.3% of participants had decrement in their health level. The results also indicate improvement in bio-energies score for five out of seven chakra points after jogging.</p>

Awareness Level of Radiation Protection among Dental Students

Dental radiographs have always been the mainstay of the diagnosis of oral diseases. Even if the radiation hazard posed by the dental radiographs is low but still accumulation of such low level radiation in human body over a time period can pose a threat to the overall health of the individual. The aim of this study is to assess the knowledge of dental students about radiation protection and hazards. The present cross sectional study was conducted by enrolling one hundred 4th year dental students from the two teaching hospitals in Chitwan district of Nepal. A questionnaire consisting of a total of 20 questions was distributed and each question was allocated 0.5 marks for correct response whereas no deduction for wrong answer. The results of the present study depicted that 85 (85%) of the total students enrolled in the study had "good" knowledge about the radiation physics, protection and hazards whereas only 15 (15%) of them had "poor" knowledge. The study concluded that teachers should involve in imparting more and more knowledge as well as training about the topic and dental curriculum should be altered so as to train the budding dentists about all aspects of radiation.