| 1. |
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| 2. |
- Giannetta, H. M. R., et al.
(författare)
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Study of the electrical parameters drift due to mechanical stress in coupled conductors path on flexible polymeric substrate
- 2022
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Ingår i: 2022 Argentine Conference on Electronics (CAE). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781728173351 - 9781728192659 ; , s. 37-40
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Konferensbidrag (refereegranskat)abstract
- In this work, the behavior of the drift in electrical impedance values of a coupled device constituting a flat rectangular inductor surrounded by a coupled antenna while subjected to mechanical stresses of over 10,000 bending-stretching cycles has been studied. It has shown correlation with mechanical aging and also is influenced by temperature variations on the device surface. The impact of the mechanical stress was studied separately for the bending-stretching and relaxation phases, considering in both cases the effect of temperature changes and mechanical stress, in order to obtain an adjustment equation for the measured experimental data.. From the fit, it was observed that when using an exponential function for the drift effect due to mechanical stress, the experimental curve was fitted with R-2=0.91 for the bending-stretching phase and R-2=0.79 for the relaxation phase.
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| 3. |
- Rangaiah, Pramod, et al.
(författare)
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Dielectric Characterization and Statistical Analysis of Ex-Vivo Burnt Human Skin Samples for Microwave Sensor Development
- 2023
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Ingår i: IEEE Access. - : IEEE. - 2169-3536. ; 11, s. 4359-4372
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Tidskriftsartikel (refereegranskat)abstract
- The dielectric properties of skin tissues in relation to different degrees of burn are a necessary prerequisite for designing non-invasive microwave sensing modalities. Due to the difficulties in obtaining human tissue samples, such databases are largely unavailable. To bridge the knowledge gap in this field, we attempt to create a dielectric database of various burn-degree skin samples and their statistical analysis in this work. This research is part of the European "Senseburn " project, which aims to create a non-invasive diagnostic tool that can measure the severity and depth of burns on humans in a clinical setting. In this work, several ex-vivo burnt samples were collected from the Uppsala University Hospital (Akademiska sjukhuset, Sweden). Out of that, eight samples with different degrees of burns in various human body locations were selected for the analysis. The dielectric characterization of the categorized samples was done using an Keysight N1501A dielectric open-end co-axial probe Kit. The dielectric characterization was made from 500 MHz to 10 GHz with 1001 points. The measurement was made systematically, and the clinician feedback forms were gathered and analyzed throughout the process. The measurement data followed the FASTCLUS procedure, which was initially analyzed using density plot, convergence, and cubic clustering criteria. For the statistical analysis, 11 frequency points were considered for eight samples. The results of the fundamental statistical analysis using the FASTCLUS procedure resulted in 88 data sets. Later, data sets were analyzed in sample-wise clusters. Every sample was made with two clusters, i.e., cluster 1, which consisted of healthy sectors, and cluster 2, which consisted of burnt sectors. We made the linear approximations for the sample-wise clusters and found the constant real permittivity difference. Furthermore, we found a pattern in the constant real permittivity differences of every sample that is proportional to the burn degrees. This information is needed in order to identify optimization parameters, i.e., the sensitivity with respect to dielectric difference for various burn degrees. For this purpose, extensive measurement campaigns across the microwave frequency band from 500 MHz - 10 GHz were conducted. Based on the analysis of dielectric data, each skin region of interest (ROI) has its own dielectric properties. Additionally, we developed a proof of concept non-invasive flexible microwave sensor based on the dielectric database collected from burnt ex-vivo human tissue samples. In this way, we could distinguish between phantoms with different dielectric properties in the burned human tissue sample range.
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| 4. |
- Rangaiah, Pramod, et al.
(författare)
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Preliminary Analysis of Burn Degree Using Non-invasive Microwave Spiral Resonator Sensor for Clinical Applications
- 2022
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Ingår i: Frontiers in Medical Technology. - : Frontiers Media S.A.. - 2673-3129. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- The European "Senseburn" project aims to develop a smart, portable, non-invasive microwave early effective diagnostic tool to assess the depth(d) and degree of burn. The objective of the work is to design and develop a convenient non-invasive microwave sensor for the analysis of the burn degree on burnt human skin. The flexible and biocompatible microwave sensor is developed using a magnetically coupled loop probe with a spiral resonator (SR). The sensor is realized with precise knowledge of the lumped element characteristics (resistor (R), an inductor (L), and a capacitor (C) RLC parameters). The estimated electrical equivalent circuit technique relies on a rigorous method enabling a comprehensive characterization of the sensor (loop probe and SR). The microwave resonator sensor with high quality factor (Q) is simulated using a CST studio suite, AWR microwave office, and fabricated on the RO 3003 substrate with a standard thickness of 0.13 mm. The sensor is prepared based on the change in dielectric property variation in the burnt skin. The sensor can detect a range of permittivity variations (ε r 3-38). The sensor is showing a good response in changing resonance frequency between 1.5 and 1.71 GHz for (ε r 3 to 38). The sensor is encapsulated with PDMS for the biocompatible property. The dimension of the sensor element is length (L) = 39 mm, width (W) = 34 mm, and thickness (T) = 1.4 mm. The software algorithm is prepared to automate the process of burn analysis. The proposed electromagnetic (EM) resonator based sensor provides a non-invasive technique to assess burn degree by monitoring the changes in resonance frequency. Most of the results are based on numerical simulation. We propose the unique circuit set up and the sensor device based on the information generated from the simulation in this article. The clinical validation of the sensor will be in our future work, where we will understand closely the practical functioning of the sensor based on burn degrees. The senseburn system is designed to support doctors to gather vital info of the injuries wirelessly and hence provide efficient treatment for burn victims, thus saving lives.
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| 5. |
- Rangaiah, Pramod, et al.
(författare)
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Realization of a Portable Semi-Shielded Chamber for Evaluation of Fat-Intrabody Communication
- 2023
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Ingår i: IEEE Access. - : IEEE. - 2169-3536. ; 11, s. 72743-72755
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a customized portable semi-shielded chamber for torso phantoms to evaluatefat-intrabody communication (Fat-IBC) is presented. Fat-IBC is a technology where human fat tissue isused for microwave communication with intrabody medical devices. The potential clinical applications arevast including central nervous system (brain and spine) communication, cardiovascular disease monitoringand metabolic disorder control. However, validating this technology needs assurance that the signal leakagethrough undesired paths, particularly surface waves and reflections, does not occur. To solve this issue,an effective technique involving a modified design of a semi-shielded chamber is presented. The cross-section of the torso phantoms is about 25 cm × 35 cm and the height about 20 cm. As specified by ISO3745:2012, the maximum object volume that can be measured in a chamber is 5% of the chamber’s internalnet volume. Therefore, the dimensions of the semi-shielded chamber was set to 100 cm × 60 cm × 60 cm.The semi-shielded chamber was constructed out of a wooden crate, covered on the inside with microwaveabsorbers and with thin aluminum sheets on the outside. The experimental evaluation of the semi-shieldedchamber was validated according to standards such as EN 50147-1:1996, IEC 61000-4-3:2020, and IECCISPR 16-1-4:2019. The torso phantom was positioned at the center of the chamber, with a separation wallto ensure signal transmission solely through the phantoms interior and not its surface or chamber walls. Theseparation wall can be modified either to be conformal to the phantom sample or serve as a solid partitiondividing the chamber into two separate volumes for performance measurement. The separation wall wasfound to have a shielding attenuation of 30 dB to 60 dB for frequencies between 0.7 GHz and 18 GHz,respectively, while the corresponding values for the external walls were found to be 45 dB to 70 dB. Thesemi-shielded chamber realized in this work is useful for Fat-IBC technology, brain-computer interface,brain-machine interface, body area networks (BANs), and related applications.
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| 6. |
- Arayeshnia, Amir, et al.
(författare)
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Miniaturized CPW-fed bowtie slot antenna for wearable biomedical applications
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008
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Konferensbidrag (refereegranskat)abstract
- A miniaturized, low -profile, flexible, and wearable ultra-wideband antenna for biomedical applications is proposed. The antenna is designed to operate in wearable conditions with the presence of multilayer biological tissues. A meandering technique is employed to reduce the electrical size of the antenna. The operational band of the proposed antenna is 0.5-4.5 GHz, while its dimensions are as small as 21x19.25x0.025 mm3. The antenna is simulated using a commercial full-wave simulator (CST Microwave Studio), fabricated on Polyethylene terephthalate (PET), and tested in realistic scenarios. The simulation and measurement results are in good compliance with each other.
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| 7. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Assessment of Blood Vessel Effect on Fat-Intrabody Communication Using Numerical and Ex-Vivo Models at 2.45 GHZ
- 2019
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Ingår i: IEEE Access. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2169-3536. ; 7, s. 89886-89900
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Tidskriftsartikel (refereegranskat)abstract
- The potential offered by the intra-body communication (IBC) over the past few years has resulted in a spike of interest for the topic, specifically for medical applications. Fat-IBC is subsequently a novel alternative technique that utilizes fat tissue as a communication channel. This work aimed to identify such transmission medium and its performance in varying blood-vessel systems at 2.45 GHz, particularly in the context of the IBC and medical applications. It incorporated three-dimensional (3D) electromagnetic simulations and laboratory investigations that implemented models of blood vessels of varying orientations, sizes, and positions. Such investigations were undertaken by using ex-vivo porcine tissues and three blood-vessel system configurations. These configurations represent extreme cases of real-life scenarios that sufficiently elucidated their principal influence on the transmission. The blood-vessel models consisted of ex-vivo muscle tissues and copper rods. The results showed that the blood vessels crossing the channel vertically contributed to 5.1 dB and 17.1 dB signal losses for muscle and copper rods, respectively, which is the worst-case scenario in the context of fat-channel with perturbance. In contrast, blood vessels aligned-longitudinally in the channel have less effect and yielded 4.5 dB and 4.2 dB signal losses for muscle and copper rods, respectively. Meanwhile, the blood vessels crossing the channel horizontally displayed 3.4 dB and 1.9 dB signal losses for muscle and copper rods, respectively, which were the smallest losses among the configurations. The laboratory investigations were in agreement with the simulations. Thus, this work substantiated the fat-IBC signal transmission variability in the context of varying blood vessel configurations.
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| 8. |
- Asan, Noor Badariah, et al.
(författare)
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Data Packet Transmission through Fat Tissue for Wireless Intra-Body Networks
- 2017
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Ingår i: IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology. - : Institute of Electrical and Electronics Engineers (IEEE). - 2469-7249 .- 2469-7257. ; 1:2, s. 43-51
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Tidskriftsartikel (refereegranskat)abstract
- This work explores high data rate microwave communication through fat tissue in order to address the wide bandwidth requirements of intra-body area networks. We have designed and carried out experiments on an IEEE 802.15.4 based WBAN prototype by measuring the performance of the fat tissue channel in terms of data packet reception with respect to tissue length and power transmission. This paper proposes and demonstrates a high data rate communication channel through fat tissue using phantom and ex-vivo environments. Here, we achieve a data packet reception of approximately 96 % in both environments. The results also show that the received signal strength drops by ~1 dBm per 10 mm in phantom and ~2 dBm per 10 mm in ex-vivo. The phantom and ex-vivo experimentations validated our approach for high data rate communication through fat tissue for intrabody network applications. The proposed method opens up new opportunities for further research in fat channel communication. This study will contribute to the successful development of high bandwidth wireless intra-body networks that support high data rate implanted, ingested, injected, or worn devices
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| 9. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Effect of Thickness Inhomogeneity in Fat Tissue on In-Body Microwave Propagation
- 2018
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Ingår i: Proceedings of the 2018 IEEE/MTT-S International Microwave Biomedical Conference (IMBIOC). - Philadelphia, USA : IEEE. - 9781538659182 ; , s. 136-138
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Konferensbidrag (refereegranskat)abstract
- In recent studies, it has been found that fat tissue can be used as a microwave communication channel. In this article, the effect of thickness inhomogeneities in fat tissues on the performance of in-body microwave communication at 2.45 GHz is investigated using phantom models. We considered two models namely concave and convex geometrical fat distribution to account for the thickness inhomogeneities. The thickness of the fat tissue is varied from 5 mm to 45 mm and the Gap between the transmitter/receiver and the starting and ending of concavity/convexity is varied from 0 mm to 25 mm for a length of 100 mm to study the behavior in the microwave propagation. The phantoms of different geometries, concave and convex, are used in this work to validate the numerical studies. It was noticed that the convex model exhibited higher signal coupling by an amount of 1 dB (simulation) and 2 dB (measurement) compared to the concave model. From the study, it was observed that the signal transmission improves up to 30 mm thick fat and reaches a plateau when the thickness is increased further.
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| 10. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Effects of Blood Vessels on Fat Channel Microwave Communication
- 2018
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Ingår i: 2018 IEEE Conference on Antenna Measurements & Applications (CAMA). - : IEEE. - 9781538657959
-
Konferensbidrag (refereegranskat)abstract
- This study aims to investigate the reliability of intra-body microwave propagation through the fat tissue in presence of blood vessels. Here, we consider three types of blood vessels with different sizes. We investigate the impact of the number of blood vessels and their alignment on the transmission of microwave signals through the fat channel. In our study, we employ two probes that act as a transmitter and a receiver. The probes are designed to operate at the Industrial, Scientific, and Medical radio band (2.45 GHz). For a channel length of 100 mm, our results indicate that the presence of the blood vessels may increase the channel path loss by similar to 1.5 dB and similar to 4.5 dB when the vessels are aligned and orthogonally aligned with the fat channel, respectively.
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| 11. |
- Asan, Noor Badariah, 1984-
(författare)
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Fat-IBC : A New Paradigm for Intra-body Communication
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the last two decades, a significant development in the field of medical technology occurred worldwide. This development is characterized by the materialization of various body implants and worn devices, that is devices attached to the body. These devices assist doctors and paramedical staff in effectively monitoring the patient’s health and helping increase patients’ average life expectancy. Furthermore, the various implants inside the human body serve different purposes according to the humans’ needs. As this situation became more prominent, the development of protocols and of reliable transmission media is becomes essential to improve the efficiency of inter-device communications. Positive prospects of the use of human tissue for intra-body communication were proven in recent studies. Fat tissues, for example, which also work as energy banks for human beings, can be potentially used in intra-body communications as transmission media. In this thesis, the fat (adipose) tissue’s function as an intra-body communication channel was investigated. Therefore, various simulations and experimentations were performed in order to characterize the reliability of the fat tissue in terms of communication, considering, for example, the effect that the variability in the thickness of adipose and muscular tissues could have on the communication performance, and the possible effect that the variability in the transmitted signal power could have on the data packet reception. Fat tissue displays superior performance in comparison to muscle tissue in the context of a low loss communication channel. For example, at 2.45 GHz, the path losses of ~0.7 dB/cm and ~1.9 dB/cm were observed for phantom and ex-vivo measurements, respectively. At a higher frequency of 5.8 GHz, the ex-vivo path loss was around 1.4 dB/cm. It was concluded from the results that the adipose tissue could function as a reliable medium supporting intra-body communication even under low power transmitted signals. Moreover, although the presence of thick blood vessels could degrade the signal strength, the results show that communication is possible even under the presence of perturbant tissues. Overall, the results of this thesis would provide a foundation in this area and assist researchers in developing innovative and solutions for intra-body communication.
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| 12. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Fat-IntraBody Communication at 5.8 GHz : Verification of Dynamic Body Movement Effects using Computer Simulation and Experiments
- 2021
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Ingår i: IEEE Access. - : IEEE. - 2169-3536. ; 9, s. 48429-48445
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents numerical modeling and experimental validation of the signal path loss at the 5.8 GHz Industrial, Scientific, and Medical (ISM) band, performed in the context of fat-intrabody communication (fat-IBC), a novel intrabody communication platform using the body-omnipresent fat tissue as the key wave-guiding medium. Such work extends our previous works at 2.0 and 2.4 GHz in the characterization of its performance in other useful frequency range. In addition, this paper also includes studies of both static and dynamic human body movements. In order to provide with a more comprehensive characterization of the communication performance at this frequency, this work focuses on investigating the path loss at different configurations of fat tissue thickness, antenna polarizations, and locations in the fat channel. We bring more realism to the experimental validation by using excised tissues from porcine cadaver as both their fat and muscle tissues have electromagnetic characteristics similar to those of human with respect to current state-of-art artificial phantom models. Moreover, for favorable signal excitation and reception in the fat-IBC model, we used topology optimized waveguide probes. These probes provide an almost flat response in the frequency range from 3.2 to 7.1 GHz which is higher than previous probes and improve the evaluation of the performance of the fat-IBC model. We also discuss various aspects of real-world scenarios by examining different models, particularly homogeneous multilayered skin, fat, and muscle tissue. To study the effect of dynamic body movements, we examine the impact of misalignment, both in space and in wave polarization, between implanted nodes. We show in particular that the use of fat-IBC techniques can be extended up in frequency to a broadband channel at 5.8 GHz.
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| 13. |
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| 14. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Human Fat Tissue : A Microwave Communication Channel
- 2017
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Ingår i: 2017 First IEEE MTT-S International Microwave Bio Conference (IMBIOC). - : IEEE. - 9781538617137
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present an approach for communication through human body tissue in the R-band frequency range. This study examines the ranges of microwave frequencies suitable for intra-body communication. The human body tissues are characterized with respect to their transmission properties using simulation modeling and phantom measurements. The variations in signal coupling with respect to different tissue thicknesses are studied. The simulation and phantom measurement results show that electromagnetic communication in the fat layer is viable with attenuation of approximately 2 dB per 20 mm.
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| 15. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Impact of Blood Vessels on Data Packet Transmission Through the Fat Channel
- 2018
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Ingår i: 2018 IEEE INTERNATIONAL RF AND MICROWAVE CONFERENCE (RFM 2018). - : IEEE conference proceedings. - 9781538667200 - 9781538667194 - 9781538667217 ; , s. 196-198
-
Konferensbidrag (refereegranskat)abstract
- The reliability of intra-body wireless communication systems is very important in medical applications to ensure the data transmission between implanted devices. In this paper, we present newly developed measurements to investigate the effect of blood vessels on the data packet reception through the fat tissue. We use an IEEE 802.15.4-based WBAN prototype to measure the packet reception rate (PRR) through a tissue-equivalent phantom model. The blood vessels are modelled using copper rods. We measure the PRR at the frequency 2.45 GHz for several power levels. The results revealed that the presence of blood vessels aligned with the fat channel has tiny influence on the PRR when measured over the range -25 dBm to 0 dBm power level and for different blood vessels positions. Our investigations show 97% successful PRR through a 10 cm length fat channel in presence of the blood vessels.
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| 16. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Intra-body microwave communication through adipose tissue
- 2017
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Ingår i: Healthcare technology letters. - : The Institution of Engineering and Technology. - 2053-3713. ; 4:4, s. 115-121
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Tidskriftsartikel (refereegranskat)abstract
- The human body can act as a medium for the transmission of electromagnetic waves in the wireless body sensor networks context. However, there are transmission losses in biological tissues due to the presence of water and salts. This Letter focuses on lateral intra-body microwave communication through different biological tissue layers and demonstrates the effect of the tissue thicknesses by comparing signal coupling in the channel. For this work, the authors utilise the R-band frequencies since it overlaps the industrial, scientific and medical radio (ISM) band. The channel model in human tissues is proposed based on electromagnetic simulations, validated using equivalent phantom and ex-vivo measurements. The phantom and ex-vivo measurements are compared with simulation modelling. The results show that electromagnetic communication is feasible in the adipose tissue layer with a low attenuation of approximate to 2 dB per 20 mm for phantom measurements and 4 dB per 20 mm for ex-vivo measurements at 2 GHz. Since the dielectric losses of human adipose tissues are almost half of ex-vivo tissue, an attenuation of around 3 dB per 20 mm is expected. The results show that human adipose tissue can be used as an intra-body communication channel.
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| 17. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Reliability of the fat tissue channel for intra-body microwave communication
- 2017
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Ingår i: 2017 IEEE Conference on Antenna Measurements & Applications (CAMA). - : IEEE. - 9781509050284 ; , s. 310-313
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Konferensbidrag (refereegranskat)abstract
- Recently, the human fat tissue has been proposed as a microwave channel for intra-body sensor applications. In this work, we assess how disturbances can prevent reliable microwave propagation through the fat channel. Perturbants of different sizes are considered. The simulation and experimental results show that efficient communication through the fat channel is possible even in the presence of perturbants such as embedded muscle layers and blood vessels. We show that the communication channel is not affected by perturbants that are smaller than 15 mm cube.
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| 18. |
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| 19. |
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| 20. |
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| 21. |
- Augustine, Robin, 1982-
(författare)
-
Arrowroot (Maranta arundinacea) is an edible starch, commercially available as powder, prepared from the roots of the plant family Marantaceae. Arrowroot is well known for its medicinal effects and use as chief ingredient in infant cookies. Arrowroot in film form is prepared and its microwave absorption characteristics, permittivity, loss factor, conductivity, skin depth, and heating coefficient are analyzed. The results are quite promising and can be concluded that arrowroot in film form is a potential candidate for several applications in medical field, when compared with well studied chitosan film
- 2009
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Ingår i: Microwave and Optical Technology Letters. ; 51:5
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Tidskriftsartikel (refereegranskat)abstract
- Arrowroot (Maranta arundinacea) is an edible starch, commercially available as powder, prepared from the roots of the plant family Marantaceae. Arrowroot is well known for its medicinal effects and use as chief ingredient in infant cookies. Arrowroot in film form is prepared and its microwave absorption characteristics, permittivity, loss factor, conductivity, skin depth, and heating coefficient are analyzed. The results are quite promising and can be concluded that arrowroot in film form is a potential candidate for several applications in medical field, when compared with well studied chitosan film
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| 22. |
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| 23. |
- Augustine, Robin, 1982-
(författare)
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Biocompatibility study of beta tricalcium phosphate bioceramics and chitosan biopolymer and their use as phantoms for medical imaging applications
- 2009
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Ingår i: Microwave and Optical Technology Letters. ; 51:12
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Tidskriftsartikel (refereegranskat)abstract
- Beta tricalcium phosphate (b-TCP) bioceramics and chitosan biopolymers are used as biomedical implants because of their better biocompatibility and good bioresorption characteristics. As they are biomaterials, they have good interactions with microwave frequencies. b-TCP and chitosan powder, films, pellets, and gel are prepared and studied at the S-band microwave frequencies. Dielectric parameters such as dielectric constant, dielectric loss, conductivity, and S-parameters are evaluated. Dielectric parameters of different forms of b-TCP and chitosan show resemblance with that of human tissues. Hence, these materials can also be considered as potential phantoms for specific absorption rate measurements as well as in microwave imaging applications. V
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| 24. |
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| 25. |
- Augustine, Robin, 1982-
(författare)
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Biocompatibility study of hydroxy apatite and chitosan composites for applications at microwave frequencies
- 2010
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Ingår i: Microwave and optical technology letters (Print). - Wiley. - 0895-2477 .- 1098-2760. ; 46:3, s. 197-199
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Tidskriftsartikel (refereegranskat)abstract
- Hydroxyapatite (HAp, Ca10(PO4)6(OH)2) bioceramic and chitosan (poly [(β-1-4) d-glucosamine]) biopolymer show good biocompatibility in vivo. They have biological origin and show excellent interactions with microwave. Microwave study of HAp made using different drying techniques and their composites with chitosan in the ISM band is presented. Pastes are made using HAp and chitosan with different ratios of mixing. The dielectric properties of this composites match with that of human fat, collagen tissues. Some of the compositions exhibit dielectric property close to that of natural bone. This makes them more biocompatible and better substitutes for natural bone. Thus composite bioceramics can be considered as phantom model constituents for imaging purposes. Their dielectric properties prove that they are biocompatible. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2931–2934, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23806
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| 26. |
- Augustine, Robin, 1982-, et al.
(författare)
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Bone Mineral Density Analysis using Ultra Wideband Microwave Measurements
- 2015
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Konferensbidrag (refereegranskat)abstract
- A novel approach to analyze the bone mineral density (BMD) based on microwave reflectivity analysis is presented in this paper. The proposed method enables us to overcome the health risks associated with diagnostic techniques such as X-rays for repeated study of the rate of mineralization in the case of fractures or de-mineralization in the case of osteoporosis. In this paper, we demonstrate the application of Microwaves for continuous observation of skull healing process during post-cranial surgery period. The proposed technique can be a potential clinical model in future for extracting target characteristics such as bone deposition thickness and other cranial defects. Based on the conclusions of wideband measured data, we propose to design the Transceiver using ultra wideband (UWB) pulsed technology.
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| 27. |
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| 28. |
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| 29. |
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| 30. |
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| 31. |
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| 32. |
- Augustine, Robin, 1982-
(författare)
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Electromagnetic modelling of human tissues and its application on the interaction between antenna and human body in the BAN context
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this age of wireless technology, Body Area networks (BAN) is revolutionising the concept of patient care and health monitoring. BAN provides people good assessment of their health status at any time, wherever they are physically. The increased interest in developing effective body (in, on & off) communication systems made phantoms which can mimic the electrical properties of an actual human body necessary. Wearable antennas which are the indispensable part of BAN got to be low pro file and above all influences that human body can make. There should also be a way to reduce the effect of antennas on human body namely specific absorption rate (SAR). In this work effort has been made to develop phantoms suitable for both On body and In body communications. The base materials which are selected for the study are of biological origin (bio ceramics and biopolymers) whose behaviour is closer to that of human tissues. As these phantoms are biocompatible they are essentially non toxic where the conventionally available phantoms are toxic in nature. Different kinds of low profile conformal wearable antennas working at 2.4GHz ISM band were developed and studied in the BAN perspective. Antennas suffer much in terms of matching and efficiency when they are in contact or in the premises of human body. This is a major hurdle in the way to setting up a good body communication network. This work encompasses various techniques adopted to limit the body interferences to an acceptable level. The techniques adopted (Such as Backing Ground Plane, High Impedance Surface & Polymeric Ferrite Sheets) proved to be effective in reducing the sway in antenna characteristics when they are mounted on body. Specific absorption rate is also brought to acceptable levels and thus avoiding the formation of hot spots due to microwave absorption. A safer and cost effective BAN can be set up using this work which will lead to a safer, mobile and healthy future.
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| 33. |
- Augustine, Robin, 1982-
(författare)
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Enhanced EMI shielding efficiency using carbon, graphite, and polyaniline blends
- 2010
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Ingår i: Microwaves and Optical technology letters. ; 52:10
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Tidskriftsartikel (refereegranskat)abstract
- Conducting polymers have found significant applications in the past decade in industrial, scientific, and medical (ISM) fields. The characteristic features of conducting polymers like reversible proton doping, variable conductivity, facile synthesis, and low cost make them potential candidates in various microelectronic applications. Conventional microwave absorbing materials such as carbon and graphite in the powder form were blended with polyaniline as base at different proportions and microwave properties such as transmission, reflection, and shielding efficiency (SE) were evaluated from S parameter measurements using HP 8714ET network analyzer. The newly developed polyaniline blend exhibits high-electromagnetic interference shielding efficiency when compared with previously developed materials and is a promising candidate for shielding applications.
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| 34. |
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| 35. |
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| 36. |
- Augustine, Robin, 1982-
(författare)
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Human skin permittivity models for the millimeter-wave range
- 2011
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Ingår i: IET Electronics Letters. ; 47, s. 427-428
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Tidskriftsartikel (refereegranskat)abstract
- The complex permittivity of the human skin has been measured in vivo in the 10 –60 GHz range using a recently developed coaxial slim probe. The results are compared with the literature data at millimetre waves, and a broad-band Cole-Cole model is proposed for several locations on the arm, namely at the palm, wrist, and forearm. This reported study provides relevant data required for studying interactions between emerging body-centric wireless millimetre-wave technologies and the human body
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| 37. |
- Augustine, Robin, 1982-
(författare)
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Interview
- 2016
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Ingår i: IET Electronics Letters. - : IET Electronics Letters. ; 52:8, s. 568-
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Forskningsöversikt (populärvet., debatt m.m.)abstract
- Professor Robin Augustine from Ångstrom Laboratory in Uppsala, Sweden talks us about the work behind his paper ‘A preliminary study on monitoring the progression of osteoporosis using UWB radar technique in distal femur model.
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- Augustine, Robin, 1982-, et al.
(författare)
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Microwave Phantoms For Craniotomy Follow-Up Probe Development
- 2014
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Ingår i: 2014 IEEE CONFERENCE ON ANTENNA MEASUREMENTS & APPLICATIONS (CAMA). - 9781479936786
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Konferensbidrag (refereegranskat)abstract
- A novel phantom for skull implant diagnostics is presented in this paper. Specially designed three layer phantom is designed for osseointegration analysis after craniotomy using 2.4 GHz microwave probe. The phantom represents skin, skull and brain, and defects are made in the skull with the dielectric profile variation of realistic implants. The extreme dielectric constant variation of implant and bone gives a high degree of discrimination in resonant frequency. The presented craniotomy phantom is very useful for designing antennas for monitoring skull healing.
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- Augustine, Robin, 1982-
(författare)
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Near-field dosimetry for the millimeter-wave exposure of human cells in vitro
- 2012
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Ingår i: Bioelectromagnetics. - 0197-8462 .- 1521-186X. ; , s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- Due to the expected mass deployment of millimeter-wave wireless technologies, thresholds of potential millimeter-wave-induced biological and health effects should be carefully assessed. The main purpose of this study is to propose, optimize, and characterize a near-field exposure configuration allowing illumination of cells in vitro at 60 GHz with power densities up to several tens of mW/cm(2) . Positioning of a tissue culture plate containing cells has been optimized in the near-field of a standard horn antenna operating at 60 GHz. The optimal position corresponds to the maximal mean-to-peak specific absorption rate (SAR) ratio over the cell monolayer, allowing the achievement of power densities up to 50 mW/cm(2) at least. Three complementary parameters have been determined and analyzed for the exposed cells, namely the power density, SAR, and temperature dynamics. The incident power density and SAR have been computed using the finite-difference time-domain (FDTD) method. The temperature dynamics at different locations inside the culture medium are measured and analyzed for various power densities. Local SAR, determined based on the initial rate of temperature rise, is in a good agreement with the computed SAR (maximal difference of 5%). For the optimized exposure setup configuration, 73% of cells are located within the ±3 dB region with respect to the average SAR. It is shown that under the considered exposure conditions, the maximal power density, local SAR, and temperature increments equal 57 mW/cm(2) , 1.4 kW/kg, and 6 °C, respectively, for the radiated power of 425 mW.
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- Augustine, Robin, 1982-, et al.
(författare)
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Polymeric ferrite sheats for SAR reduction of Wearable ANtennas
- 2010
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Ingår i: Electronics Letters. - UK : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 46:3, s. 197-198
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Tidskriftsartikel (refereegranskat)abstract
- Reduction of specific absorption rate (SAR) has now become a buzz word because of the growing health concerns over microwave exposure. Ferrites are found to be effective in diminishing electromagnetic influence. In this reported work, flexible polymeric ferrite sheets are characterised on the basis of their shielding efficiencies. SAR measurements are carried out with a planar wearable antenna and polymeric ferrite shielding to confirm its competence.
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