| 1. |
- Basu, Subhadeep, et al.
(författare)
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Antenna Based RF Techniques for Intrabody Communication
- 2020
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Ingår i: 2020 IEEE MTT-S International Microwave Biomedical Conference (IMBioC). - 9781728158679 - 9781728158662
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Konferensbidrag (refereegranskat)abstract
- In this paper, an approach for Intrabody communication(IBC) that uses fat as the communication medium is presented in the ISM band. This study focuses on microwave communication through different biological tissue layers and demonstrates the effect of the thickness of the fat layer on transmission coefficients. Also, the Specific Absorption Rate(SAR) analysis of the antenna has been studied. To validate the simulation results, experimental verification is performed on porcine tissue.
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| 2. |
- Das, Goutam Kumar, et al.
(författare)
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Gain-enhancement technique for wearable patch antenna using grounded metamaterial
- 2020
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Ingår i: IET Microwaves, Antennas & Propagation. - : Institution of Engineering and Technology (IET). - 1751-8725 .- 1751-8733. ; 14:15, s. 2045-2052
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a metamaterial (MTM)-based high-gain compact-wearable antenna for 2.45 GHz industrial, scientific and medical radio band application has been proposed. To achieve the flexibility of the antenna, textile material felt fabric has been chosen as the substrate of the antenna as well as MTM. An omega (omega) like structure has been taken as MTM unit cell design. High value of permeability is utilised for the gain enhancement of the antenna. In addition, very low specific absorption rate (SAR) is obtained using the MTM which makes the proposed antenna suitable for the biomedical application. The proposed antenna has achieved about 3 dB gain enhancement along with SAR value of 0.405 W/kg (1 g tissue). The design has been optimised and the prototype with the optimised parameter has been fabricated and tested over the semi-solid phantom and human body. Further, the proposed antenna over different type of textile material has also been validated.
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| 3. |
- Das, Soumyadeep, et al.
(författare)
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A novel SAR reduction technique for implantable antenna using conformal absorber metasurface
- 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
- In this paper, a conformal absorber metasurface has been designed and used for reducing the specific absorption rate (SAR) of an implantable antenna. SAR reduction of implantable antennas is one of the significant design aspects to be considered for their use in modern-day healthcare applications. The introduction of the absorber metasurface restricts the back radiation of the antenna to control the SAR value. This technique decreases the maximum SAR value by 24% and also reduces the average SAR distribution significantly without affecting the desired antenna gain. A reduction in SAR value indicates the decrease in radiation absorption by human tissue, and thus, decreases the possibility of health hazards due to EM radiation. Later, this antenna-absorber system is designed as a capsule module for increased mobility and less-invasiveness. The redundancy of invasive surgery increases acceptance of the capsule module designs of implantable antennas and devices for various biomedical usages. In vitro testing of the fabricated prototype has been carried out inside a multi-layer porcine slab to verify the effectiveness of this unique SAR reduction technique.
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| 4. |
- Das, Soumyadeep, et al.
(författare)
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Implantable antenna gain enhancement using liquid metal-based reflector
- 2020
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Ingår i: Applied Physics A. - : SPRINGER HEIDELBERG. - 0947-8396 .- 1432-0630. ; 126:9
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Tidskriftsartikel (refereegranskat)abstract
- This article presents gain enhancement methodology for a dual-ring slot antenna using a frequency selective surface (FSS) as reflector. The FSS structure is formed with liquid metal placed inside the microfluidic channels created on the surface of the polydimethylsiloxane. Non-toxic liquid metal galinstain has been used to ensure biocompatibility. The FSS structure is placed below the ring slot antenna to reflect the back radiation, which in turn enhances the antenna directivity. Subsequently, the antenna gain has been increased as well. A fabricated prototype of the antenna-FSS system, operating at 2.45 GHz, has been analysed both inside human tissue mimicking fluid and pork slab to validate the simulation results. The inclusion of the liquid metal-based reflector increases antenna gain by almost 4 dB as well as ensures required biocompatibility and flexibility. Also the specific absorption rate of the antenna is observed to be reduced.
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| 5. |
- Ebrahimizadeh, Javad, et al.
(författare)
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Time Reversal Microwave Imaging of Realistic Numerical Head Phantom for Bone Flap Healing Follow-up
- 2020
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Ingår i: 2020 IEEE MTT-S International Microwave Biomedical Conference (IMBioC). - 9781728158662 - 9781728158679
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Konferensbidrag (refereegranskat)abstract
- This paper presents the feasibility of using a microwave imaging system for monitoring bone mineralization progress overtime after craniotomy surgery. Any variation in the composition of the bone flap can be monitored as a variation in the intensity of the image. A simulation is conducted on a head structure derived from a numerical head phantom based on anatomically realistic MRI-derived FDTD models using commercial CST 2019 software. For simulation, a defect is provided in the skull layer surrounded by a 9-elements antenna. Applying Space-Frequency Time Reversal (TR) method, the image of defect is constructed for different permittivity of the defect ranging from 16 to 36. Results show that the image intensity at the defect location will decrease as the permittivity of the defect decreases.
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| 6. |
- Engstrand, Johan, et al.
(författare)
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End-to-End Transmission of Physiological Data from Implanted Devices to a Cloud-Enabled Aggregator Using Fat Intra-Body Communication in a Live Porcine Model
- 2022
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Ingår i: 2022 16TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP). - : Institute of Electrical and Electronics Engineers (IEEE). - 9788831299046 - 9781665416047
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Konferensbidrag (refereegranskat)abstract
- This article presents, for the first time, the end-to-end transmission of physiological data from implanted antennas mimicking sensors to a cloud-enabled aggregator device using fat intra-body communication (fat-IBC). The experiment was performed on a live porcine model in full accordance with ethical standards. Measurement data from two different sensors were collected and sent through a fat-IBC network. The fat-IBC network consisted of three nodes, of which two used antennas implanted in the fat tissue of a live porcine model and one used an on-body antenna placed on the skin. The sensor data was forwarded via Bluetooth Low Energy to an Intel Health Application Platform device, which in turn forwarded the encrypted data to a web server. The experimental results demonstrate that the fat channel can be used in an end-to-end communication scheme, which could involve relaying of sensor data from an implanted device to an external web server.
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| 7. |
- Gaffoglio, Rossella, et al.
(författare)
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Compact Optimized Antenna Solution for Radiation Coupling Improvement in the Subcutaneous Fat Layer
- 2023
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Ingår i: 2023 17th European Conference on Antennas and Propagation, EuCAP. - : IEEE. - 9788831299077 - 9781665475419
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Konferensbidrag (refereegranskat)abstract
- Fat intra-body communication (Fat-IBC) aims at confining microwave propagation to the subcutaneous adipose tissue layer for the creation of a safe high-speed, high-bandwidth data transmission link through the body. This technique can be exploited to connect implantable medical devices and to implement a two-way transmission of recorded neural data and sensory stimulation signals between brain and robotic limbs. In this paper, a compact printed antenna solution for non-invasive tests of the Fat-IBC on non-human primates (NHPs) is proposed. This antenna is a printed monopole with a triangular radiating element embedded into a rigid brick, properly optimized to favor the radiation coupling in a 5mm-thick fat layer and minimize the signal propagation through the air. A promising wave coupling in the adipose tissue is achieved and a compact realizable layout is finalized for future prototyping and testing.
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| 8. |
- 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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| 9. |
- Krentz, Konrad-Felix, et al.
(författare)
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Dataset: Enabling Offline Tuning of Fat Channel Communication
- 2021
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Ingår i: Proceedings of the 19th ACM Conference on Embedded Networked Sensor Systems (SenSys '21). - New York, NY, USA : ACM.
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Konferensbidrag (refereegranskat)abstract
- Though fat channel communication has advantages over earlier intra-body communication (IBC) technologies based on galvanic or capacitive coupling, the development of a protocol stack on top of fat channel communication is still at its infancy. In this paper, we consider Krentz’s denial-of-sleep-resilient multi-channel medium access control (MAC) layer for IEEE 802.15.4 networks as a starting point for such a protocol stack. In brief, we conducted the following experiment with a phantom that mimics human tissues. Two devices exchanged IEEE 802.15.4 radio frames in a ping-pong manner on the phantom’s fat tissue using Krentz’s MAC layer. The data collected from this experiment lends itself to two purposes. First, it can serve to benchmark and tune algorithms for selecting radio channels. Second, it can also serve to benchmark and tune schemes for deriving cryptographic keys from received signal strength indicator (RSSI) readings. We made the data available at https://uppsala.box.com/s/z2a6jpigswpoifd5l73yophokcfwd88b.
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| 10. |
- Mandal, Bappaditya, et al.
(författare)
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A Low Profile Button Antenna with Back Radiation Reduced By FSS
- 2020
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Ingår i: 2020 14th European Conference on Antennas and Propagation (EuCAP). - 9788831299008 - 9781728137124
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Konferensbidrag (refereegranskat)abstract
- In this article, a button antenna with a reflective frequency selective surface(FSS) is proposed to reduce its back radiation. The proposed antenna is low in profile, circularly polarized and designed for Wi-Fi and WLAN applications. The radiating element is made of copper sheet, while a transparent acrylic fibre sheet is used as a substrate. The antenna is fed by a coaxial line, and the FSS layer is designed on jeans material. The patch type FSS with split ring shape has also been designed to operate in the Wi-Fi and WLAN frequency hand (5.250-5.850 GHz) with the centre frequency of 5.51 GHz. The FSS reduces hack radiation of the antenna by 4 dB. The antenna with FSS is fabricated, and a measured gain of 2.9dBi is obtained that matches well with the theoretical value. The antenna is miniaturized by around 61.15% by the slits. To achieve circular polarization characteristic Defected Ground Structure (DGS) slots etched at the ground plane of the triangular patch. The measured impedance bandwidth is 190MHz, and the 3dB axial-ratio (AR) bandwidth is 160MHz, respectively.
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