| 1. |
- 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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| 2. |
- Mitra, Shamba, et al.
(författare)
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Hip Implant Micromotion monitoring using microwave-photonic hybrid device
- 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
- In this work, our objective is to develop a noninvasive, portable, user-friendly, non-ionizing, cost-effective system that will be used for post-surgical continuous monitoring of hip implant micromotion. The system we have tried to construct here has been built by integrating microwave sensors and optical interferometric systems. A simple antenna and optoelectrical modulator have been used to devise this hybrid system. Proof of the concept of this novel idea has also been established.
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| 3. |
- 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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| 4. |
- 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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| 5. |
- 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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| 6. |
- Dey, Samiran, et al.
(författare)
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BliMSR : Blind Degradation Modelling for Generating High-Resolution Medical Images
- 2024
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Ingår i: MEDICAL IMAGE UNDERSTANDING AND ANALYSIS, MIUA 2023. - : Springer Nature. - 9783031485923 - 9783031485930 ; , s. 64-78
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Konferensbidrag (refereegranskat)abstract
- A persisting problem with existing super-resolution (SR) models is that they cannot produce minute details of anatomical structures, pathologies, and textures critical for proper diagnosis. This is mainly because they assume specific degradations like bicubic downsampling or Gaussian noise, whereas, in practice, the degradations can be more complex and hence need to be modelled "blindly". We propose a novel attention-based GAN model for medical image super-resolution that models the degradation in a data-driven agnostic way ("blind") to achieve better fidelity of diagnostic features in medical images. We introduce a new ensemble loss in the generator that boosts performance and a spectral normalisation in the discriminator to enhance stability. Experimental results on lung CT scans demonstrate that our model, BliMSR, produces super-resolved images with enhanced details and textures and outperforms recent competing models, including a diffusion model for generating super-resolution images, thus establishing a state-of-the-art. The code is available at https://github.com/Samiran-Dey/BliMSR.
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| 7. |
- Mandal, Bappaditya, et al.
(författare)
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Low Profile Implantable Antenna for Fat Intra-Body Communication
- 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
- A flexible low profile biocompatible implantable antenna for fat intra-body communication is presented. This article gives an idea of fat channel communication at different distances. The antenna is designed on 0.25 mm thick low loss taconic material. The antenna is covered by 0.1 mm thick PDMS (Polydimethylsiloxane) to ensure biocompatibility with human tissue. A coplanar wave (CPW) microstrip line is used to feed the antenna. This antenna has been optimized to operate at the 2.4 GHz hand frequency in the human three -layer tissue model The simulation, as well as measurement, were done at a minimum distance of 10 mm, and the maximum distance of 70mm between of two implantable antennas. The measured path loss of the fat channel by using the proposed implantable antenna is estimated to be almost 2.5 dB per centimetre. The measured bandwidth of the proposed antenna found to be 660 MHz.
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| 8. |
- Shaw, Tarakeswar, et al.
(författare)
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Design of Metamaterial Based Efficient Wireless Power Transfer System Utilizing Antenna Topology for Wearable Devices
- 2021
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Ingår i: Sensors. - : MDPI. - 1424-8220. ; 21:10
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Tidskriftsartikel (refereegranskat)abstract
- In this article, the design of an efficient wireless power transfer (WPT) system using antenna-based topology for the applications in wearable devices is presented. To implement the wearable WPT system, a simple circular patch antenna is initially designed on a flexible felt substrate by placing over a three-layer human tissue model to utilize as a receiving element. Meanwhile, a high gain circular patch antenna is also designed in the air environment to use as a transmitter for designing the wearable WPT link. The proposed WPT system is built to operate at the industrial, scientific and medical (ISM) band of 2.40-2.48 GHz. In addition, to improve the power transfer efficiency (PTE) of the system, a metamaterial (MTM) slab built with an array combination of 3 x 3 unit cells has been employed. Further, the performance analysis of the MTM integrated system is performed on the different portions of the human body like hand, head and torso model to present the versatile applicability of the system. Moreover, analysis of the specific absorption rate (SAR) has been performed in different wearable scenarios to show the effect on the human body under the standard recommended limits. Regarding the practical application issues, the performance stability analysis of the proposed system due to the misalignment and flexibility of the Rx antenna is executed. Finally, the prototypes are fabricated and experimental validation is performed on several realistic wearable platforms like three-layer pork tissue slab, human hand, head and body. The simulated and measured result confirms that by using the MTM slab, a significant amount of the PTE improvement is obtained from the proposed system.
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| 9. |
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| 10. |
- Shaw, Tarakeswar, et al.
(författare)
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Efficient Wireless Power Transfer System for Implantable Medical Devices Using Circular Polarized Antennas
- 2021
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Ingår i: IEEE Transactions on Antennas and Propagation. - : IEEE. - 0018-926X .- 1558-2221. ; 69:7, s. 4109-4122
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Tidskriftsartikel (refereegranskat)abstract
- In this article, we present a novel approach for designing a rotation insensitive, biocompatible, circular polarization-based efficient wireless power transfer (WPT) system for implantable medical devices (IMDs) in the radiative near-field region. Initially, a wideband, biocompatible, flexible circular polarized (CP) slot antenna is designed inside a single-layer skin tissue model to use as a receiving (Rx) element. To create the WPT link, a simple square patch antenna with the truncated corners is constructed to utilize as a transmitting (Tx) element. Furthermore, a polarization conversion-based metamaterial (MTM) structure is built particularly to improve the power transfer efficiency (PTE) of the proposed WPT system. Also, to show the versatility, the performance analysis of the proposed MTM integrated WPT system is conducted inside the human torso and head model. Moreover, a detailed study of the specific absorption rate (SAR) is accomplished regarding the safety of the human body in the light of IEEE regulation. Finally, the prototypes of the proposed WPT system are fabricated and experimentally verified in skin-mimicking gel and minced pork. The experimental result confirms the feasibility of the proposed concept by enhancing the PTE of the presented system by the usage of the MTM slab.
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