| 1. |
- 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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| 2. |
- 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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| 3. |
- Augustine, Robin, et al.
(författare)
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Microwave reflectivity analysis of bone mineral density using ultra wide band antenna
- 2017
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Ingår i: Microwave and optical technology letters (Print). - : Wiley. - 0895-2477 .- 1098-2760. ; 59:1, s. 21-26
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, an approach to analyze the bone mineral density (BMD) based on microwave reflectivity is presented 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. The proposed method is used to 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 and signal processing techniques, we propose to design the Transceiver using ultra-wideband (UWB) pulsed technology.
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| 4. |
- Augustine, Robin, et al.
(författare)
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Relative permittivity measurements of Et-OH and Mt-OH mixtures for calibration standards in 1-15 GHz range
- 2014
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 50:5, s. 358-359
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Tidskriftsartikel (refereegranskat)abstract
- In open-ended coaxial dielectric characterisation techniques, intermediate liquid standards between air and water are necessary for precise dielectric measurements of biological samples. Calibration standards with dielectric permittivities much different from those of the measured samples will produce unreliable results. Different intermediate calibration standards are prepared and measurement results are presented. The aim is to obtain various permittivity values between 10 and 80 by diluting methanol and ethanol with distilled water. This technique can also be used for assessing the purity of alcohols.
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| 5. |
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| 6. |
- Mathur, Phalguni, et al.
(författare)
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Dual MIMO Antenna System for 5G Mobile Phones, 5.2 GHz WLAN, 5.5 GHz WiMAX and 5.8/6 GHz WiFi Applications
- 2021
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Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 9, s. 106734-106742
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Tidskriftsartikel (refereegranskat)abstract
- A multi-purpose dual Multiple-Input-Multiple-Output (MIMO) antenna system for 5G mobile systems is presented in this paper. The proposed antenna consists of two sets of MIMO antennas on a single board. The 8-port MIMO antenna, placed on the board, is working over 3.5 GHz (3.4 GHz-3.6 GHz) 5G band with dimensions 150 mm x 70 mm. The 4-port MIMO system, placed on the chassis, is operating over 5.2 GHz WLAN/5.5 GHz WiMAX/5.8 GHz/6 GHz WiFi band with dimensions 20 mm x 7 mm. The prototype is designed and fabricated on FR4 (epsilon(r) = 4.4 and tan delta = 0.02) substrate with 0.8 mm thickness. The overall design of the entire dual MIMO system is very minimal leaving ample space for other components to be placed on the board. The presence of two separate MIMO antennas in the proposed prototype aids in using the 5G frequencies and 4G frequencies independently. Since no active elements like diodes, switches etc. are involved in the proposed design to switch between different bands, the prototype is free from any ohmic losses. It is also worth noticing that the proposed antenna operates in the highly anticipated next generation WiFi 6E spectrum.
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| 7. |
- Nijas, C. M., et al.
(författare)
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Low-Cost Multiple-Bit Encoded Chipless RFID Tag Using Stepped Impedance Resonator
- 2014
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 62:9, s. 4762-4770
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Tidskriftsartikel (refereegranskat)abstract
- A novel compact multiple-bit encoded chipless RFID tag using a stepped impedance resonator (SIR) is proposed. The main advantage of SIR compared with other resonators is the independent control over the fundamental as well as first harmonic frequency by varying either the impedance ratio (K) or length ratio (alpha). The tag utilizes both the fundamental and the first harmonic frequency of the SIR to represent two bit information with a single resonator. The tag is capable of representing 2(2N) number of bit combinations with resonators. RFID tags are fabricated on C-MET LK4.3 and (epsilon(r) = 4.3 and tan delta = 0.0018) and RT Duriod (epsilon(r) = 2.2 and tan delta = 0.0009) substrates. The structural information of the tag is encoded in the frequency spectrum, both in the magnitude and group delay of the backscattered signal. The data encoding capacity of the tag is enhanced by using the frequency shift coding technique. The proposed RFID tags have an operating range of 50 cm in the outdoor environment. Theoretical and numerical methods are used to verify the measured resonant frequencies of the tag.
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| 8. |
- Perez, Mauricio D., et al.
(författare)
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Head-compliant microstrip split ring resonator for non-invasive healing monitoring after craniosynostosis-based surgery
- 2020
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Ingår i: HEALTHCARE TECHNOLOGY LETTERS. - : INST ENGINEERING TECHNOLOGY-IET. - 2053-3713. ; 7:1, s. 29-34
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Tidskriftsartikel (refereegranskat)abstract
- A soft and highly directive, proximity-coupled split-ring resonator fabricated with a liquid alloy, copper and polydimethylsiloxane (PDMS) is presented. The same was designed for sensing osteogenesis of calvarial bone. As dielectric properties of bone grafts in ossifying calvarial defects should change during the osteogenesis process, devices like this could monitor the gradual transformation of the defect into bone by differentiating changes in the dielectric properties as shifts in the resonance frequency. Computational Software Technology (CST) Microwave Studio (R)-based simulation results on computational head models were in good agreement with laboratory results on head phantom models, which also included the comparison with an in-vivo measurement on the human head. A discussion based on an inductive reasoning regarding dynamics' considerations is provided as well. Since the skin elasticity of newborn children is high, stretching and crumpling could be significant. In addition, due to typical head curvatures in newborn children, bending should not be a significant issue, and can provide higher energy focus in the defect area and improve conformability. The present concept could support the development of soft, cheap and portable follow-up monitoring systems to use in outpatient hospital and home care settings for post-operative monitoring of bone healing after reconstructive surgical procedures.
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| 9. |
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| 10. |
- Raman, Sujith, et al.
(författare)
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Geometrical and Dimensional Dependance of Skull Implants on Oseointegration Analysis Using Microwave Probe
- 2014
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Ingår i: 2014 IEEE CONFERENCE ON ANTENNA MEASUREMENTS & APPLICATIONS (CAMA). - 9781479936786
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Konferensbidrag (refereegranskat)abstract
- This paper present the geometrical and dimensional dependence of implants during the healing analysis. The healing analysis is done using microwave antenna based on a split ring resonator. Microwave antenna for osseointegration is done for the first time. The prototypes fabricated in three different substrates are measured using head phantoms with different implant geometry and dimension. The knowledge about the dependency on implant geometry and dimension is useful for the surgeons to have a proper selection of implants.
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| 11. |
- Raman, Sujith, et al.
(författare)
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Noninvasive Osseointegration Analysis of Skull Implants With Proximity Coupled Split Ring Resonator Antenna
- 2014
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 62:11, s. 5431-5436
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Tidskriftsartikel (refereegranskat)abstract
- A novel technique for skull implant diagnostics is presented in this paper. Specially designed highly directive antenna is used for osseointegration analysis with respect to the dielectric profile variation of the implant. The extreme dielectric constant variation of implant and bone gives a high degree of discrimination in the resonant frequency of the antenna. Special care is taken in antenna design to give a perfect matching and to keep the resonant frequency band width for different background properties. The antenna simulated on three different substrates is fabricated and experimentally verified with phantom models.
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| 12. |
- Raman, Sujith, et al.
(författare)
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Osseointegration analysis of skull implants using microstrip fed split ring resonator antenna
- 2014
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Ingår i: 2014 XXXITH URSI General Assembly And Scientific Symposium (URSI GASS).
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Konferensbidrag (refereegranskat)abstract
- A microwave technique for skull implant curing analysis is presented here. A microstrip antenna is used for osseointegration analysis with respect to the dielectric profile variation of the implant. The bone and implant gives a high degree of discrimination in resonant frequency of reflection coefficient. The prototype is designed to retain the impedance matching at all implant conditions and even in normal phantom. The antennas simulated on three different substrates layers are fabricated and concept is experimentally verified with phantom models.
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