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  • 51.
    Augustine, Robin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Complex dielectric permittivity measurements of human skin and biological solution in 2-67GHz range2012Conference paper (Refereed)
  • 52. Augustine, Robin
    et al.
    Thierry, Alves
    Sarrebourse, T.
    Poussot, B.
    Mathew, K. T.
    Laheurte, J. -M.
    Polymeric ferrite sheats for SAR reduction of Wearable ANtennas2010In: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 46, no 3, p. 197-198Article in journal (Refereed)
    Abstract [en]

    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.

  • 53.
    Dancila, Dragos
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Töpfer, Fritzi
    KTH Royal Inst Technol, Stockholm, Sweden.
    Dudorov, Sergey
    KTH Royal Inst Technol, Stockholm, Sweden.
    Hu, Xin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Emtestam, Lennart
    Karolinska Inst, Div Dermatol & Venereol, Stockholm, Sweden.
    Tenerz, Lars
    Optiga AB, Uppsala, Sweden.
    Oberhammer, Jachim
    KTH Royal Inst Technol, Stockholm, Sweden.
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Millimeter wave silicon micromachined waveguide probe as an aid for skin diagnosis - results of measurements on phantom material with varied water content2014In: Skin research and technology, ISSN 0909-752X, E-ISSN 1600-0846, Vol. 20, no 1, p. 116-123Article in journal (Refereed)
    Abstract [en]

    Background

    More than 2 million cases of skin cancer are diagnosed annually in the United States, which makes it the most common form of cancer in that country. Early detection of cancer usually results in less extensive treatment and better outcome for the patient. Millimeter wave silicon micromachined waveguide probe is foreseen as an aid for skin diagnosis, which is currently based on visual inspection followed by biopsy, in cases where the macroscopical picture raises suspicion of malignancy.

    Aims

    Demonstration of the discrimination potential of tissues of different water content using a novel micromachined silicon waveguide probe. Secondarily, the silicon probe miniaturization till an inspection area of 600 x 200 m2, representing a drastic reduction by 96.3% of the probing area, in comparison with a conventional WR-10 waveguide. The high planar resolution is required for histology and early-state skin-cancer detection.

    Material and methods

    To evaluate the probe three phantoms with different water contents, i.e. 50%, 75% and 95%, mimicking dielectric properties of human skin were characterized in the frequency range of 95-105GHz. The complex permittivity values of the skin are obtained from the variation in frequency and amplitude of the reflection coefficient (S11), measured with a Vector Network Analyzer (VNA), by comparison with finite elements simulations of the measurement set-up, using the commercially available software, HFSS. The expected frequency variation is calculated with HFSS and is based on extrapolated complex permittivities, using one relaxation Debye model from permittivity measurements obtained using the Agilent probe.

    Results

    Millimeter wave reflection measurements were performed using the probe in the frequency range of 95-105GHz with three phantoms materials and air. Intermediate measurement results are in good agreement with HFSS simulations, based on the extrapolated complex permittivity. The resonance frequency lowers, from the idle situation when it is probing air, respectively by 0.7, 1.2 and 4.26GHz when a phantom material of 50%, 75% and 95% water content is measured.

    Discussion

    The results of the measurements in our laboratory set-up with three different phantoms indicate that the probe may be able to discriminate between normal and pathological skin tissue, improving the spatial resolution in histology and on skin measurements, due to the highly reduced area of probing.

    Conclusion

    The probe has the potential to discriminate between normal and pathological skin tissue. Further, improved information, compared to the optical histological inspection can be obtained, i.e. the complex permittivity characterization is obtained with a high resolution, due to the highly reduced measurement area of the probe tip.

  • 54.
    Dancila, Dragos
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Beuerle, Bernhard
    Micro and Nanosystems, Royal Institute of Technology (KTH).
    Shah, Umer
    Micro and Nanosystems, Royal Institute of Technology (KTH).
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Gustafsson, Andreas
    Department of Radar Systems, Swedish Defence Research Agency (FOI).
    Oberhammer, Joachim
    Micro and Nanosystems, Royal Institute of Technology (KTH).
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Leaky Wave Antenna at 300 GHz in KTH’s Micromachined Waveguide Technology2018Conference paper (Other academic)
  • 55.
    Dancila, Dragos
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Malmqvist, Robert
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Reyaz, Shakila Bint
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Samuelsson, C.
    Kaynak, M.
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Wide Band On-Chip Slot Antenna with Back-Side Etched Trench for W-band Sensing Applications2013In: 2013 7th European Conference on Antennas and Propagation (EuCAP), 2013, p. 1576-1579Conference paper (Refereed)
    Abstract [en]

    This paper presents the design and characterization of a highly integrated, wideband on-chip radiometer, composed of a slot antenna, RF-MEMS Dicke Switch, LNA and a wideband power detector. The highly integrated single-chip RF front-end is dedicated for broadband sensing up to 110 GHz. Both antenna and radiometer are fabricated in a 0.25 mu m SiGe BiCMOS process. The antenna design takes benefit of the back-side etched trench, offered by the technology. This is used to reduce losses due to the presence of the low resistivity silicon substrate. Additionally, the trench is specially shaped, as to improve the wideband matching of the antenna. The on-chip slot antenna design covers a wide bandwidth (70-110 GHz) with 0 dBi gain and 64% efficiency, both simulated at 94 GHz. The measured bandwidth spans 85 to 105 GHz. The W-band SiGe detector circuit has close to 20 GHz of operational bandwidth (S-11 <=-10 dB at 75-92 GHz) and presents a responsivity of 3-5kV/W (NEP=10-16 pW/Hz(1/2)) at 83-94 GHz.

  • 56.
    Ebrahimizadeh, Javad
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. Univ Tehran, Sch Elect & Comp Engn, Tehran, Iran.
    Perez, Mauricio D.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Electromagnetic Time-Reversal Technique for Monitoring Skull Healing Stages2019In: 2019 13th European Conference On Antennas And Propagation (EuCAP), IEEE , 2019Conference paper (Refereed)
    Abstract [en]

    This paper provides a novel non-resonant spectroscopy technique for monitoring of the healing process in skull defects created in cranial surgery. Currently, there is not such a method and information on the healing process which is vital to avoid further complications and for a better understanding of the process. During the healing, which can take several months, the thickness and the permittivity of the skull varies. The proposed approach makes use of the approximated Dyadic Green's function integral equation for deriving the variations in permittivity of the skull. The scattered electric field from the defect is collected using Time-Reversal Array (TRA) in order to produce the Multi-StaticData Matrix (MDM). The singular value decomposition on the MDM matrix based on time reversal operator (TRO) decomposition (known under French acronym DORT), provides information of the permittivity of the defect. The problem of the sensing the defect response after the cranial surgery is formulated for multi-layer medium and it will be shown that the dominant singular values are corresponding to the permittivity of the defect. Finally, the veracity of the theory is clarified by conducting a numerical simulation for a planar multi-layer medium consisting of skin, skull brain and a defect embedded in the skull. We show that the dominant singular values corresponding to the defect permittivity vary significantly which conclude that the dominant singular value can be a good criterion for monitoring the skull healing stages.

  • 57. Hassan, Emadeldeen
    et al.
    Noreland, Daniel
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Wadbro, Eddie
    Berggren, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Topology Optimization of Planar Antennas for Wideband Near-Field Coupling2015In: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221, Vol. 63, no 9, p. 4208-4213Article in journal (Refereed)
    Abstract [en]

    We present an approach to design from scratch planar microwave antennas for the purpose of ultra-wideband (UWB) near-field sensing. Up to about 120 000 design variables associated with square grids on planar substrates are subject to design, and a numerical optimization algorithm decides, after around 200 iterations, for each edge in the grid whether it should consist of metal or a dielectric. The antenna layouts produced with this approach show UWB impedance matching properties and near-field coupling coefficients that are flat over a much wider frequency range than a standard UWB antenna. The properties of the optimized antennas are successfully cross-verified with a commercial software and, for one of the designs, also validated experimentally. We demonstrate that an antenna optimized in this way shows a high sensitivity when used for near-field detection of a phantom with dielectric properties representative of muscle tissue.

  • 58. Lee, D
    et al.
    Velander, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Blockhuis, T. J.
    Kim, K
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    A preliminary study on monitoring the progression of osteoporosis using UWB radar technique in distal femur model2016In: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 52, no 8, p. 589-590Article in journal (Refereed)
    Abstract [en]

    In this Letter, the preliminary study on the progression of osteoporosis using ultra wide band radar technique suggesting two different cases, (1) For various bone thickness and (2) For different effective permittivity is presented. To monitor the progression of osteoporosis, resistively loaded dipole antenna was designed and used as a sensor. For use in targets representing intermediate stages of progression, methanol, ethanol, water, and wood were used for emulating effective dielectric constant of bone in real situation. Measurement results show consistent decrease in the enveloped difference voltage in the two cases which correlate to the loss of bone mineral density. In the future, these results will be useful for people with osteoporosis to predict fractures in advance.

  • 59.
    Lee, Doojin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Nowinski, Daniel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Plastic Surgery.
    Investigation of Skull Defect using Resistive Dipole Antenna on Cranial Surgery Phantom Model2017In: 2017 IEEE Conference on Antenna Measurements & Applications (Cama), IEEE, 2017, p. 301-303Conference paper (Other academic)
    Abstract [en]

    In this work, the resistive dipole antenna is designed for sensing the effective dielectric constants of the skull defect as part of the healing stages for craniosynostosis. The performance of the fabricated resistive dipole antenna is analyzed by comparing to the conventional dipole antenna in terms of both frequency and time domain. The measurement result is shown that the amplitude of the reflected pulse is increased as the thickness of the powder is increased.

  • 60.
    Lee, Doojin
    et al.
    Gwangju Inst Sci & Technol, Dept Biomed Sci & Engn, Gwangju, South Korea.
    Kim, Kangwook
    Gwangju Inst Sci & Technol, Dept Biomed Sci & Engn, Gwangju, South Korea.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Monitoring of the Skull Healing within Layered Head Model Based on Transmission Line Theory2017In: 2017 1st IEEE MTT-S International Microwave Bio Conference (IMBioC), 2017Conference paper (Refereed)
    Abstract [en]

    The possibility of monitoring the skull healing after craniotomy using microwaves is studied. The layered head model is constructed using transmission line. The reflected pulse for each layer can then be obtained and is used to monitor the skull healing. The dispersive dielectric profiles for each layer are considered. The simulation results show that the shifts from reflected pulse at skull-brain interface can be monitored as the skull thickness is varied from 0mm to 10mm.

  • 61.
    Lee, Doojin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Nowinski, Daniel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Plastic Surgery.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    A UWB sensor based on resistively-loaded dipole antenna for skull healing on cranial surgery phantom models2018In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 60, no 4, p. 897-905Article in journal (Refereed)
    Abstract [en]

    After craniotomy, the monitoring of the skull healing progression is strongly needed to take a proper medical intervention. The CT scans is however currently used for follow-up after craniotomy resulting in lack of an effective and safety problem. This research proposes an alternative for monitoring the skull healing using ultra-wide band (UWB) antenna. For the healing of the skull surgical defect, a compact resistively-loaded dipole antenna is designed and analyzed in terms of its performance in the time domain. The head phantoms having a wideband characteristic are fabricated and used as models for the skull healing process. To represent various mineralization stages, phantoms with various dielectric constants from hydrogel scaffold to the normal skull and their intermediate values are used. The UWB radar technique in the time domain is implemented in the healing process of skull injuries emulating cranial cavities that are made as part of craniosynostosis treatment. The measurement results at the defect area show that the variations in amplitude of the reflected pulse as the skull healing is progressed. The results obtained can contribute to the development of microwave-based techniques as a preliminary study of a proof concept before clinical trial in the healing process after cranial surgery.

  • 62.
    Lee, Doojin
    et al.
    UW, Mech & Mechatron Engn, Waterloo, ON, Canada.
    Shaker, George
    UW, Mech & Mechatron Engn, Waterloo, ON, Canada.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Imaging of Defect Responses on Cranial Vault Phantom Model utilizing Curved Array Measurement2019In: 2019 13th European Conference On Antennas And Propagation (EUCAP), IEEE , 2019Conference paper (Refereed)
    Abstract [en]

    This paper presents the reconstructed curved images after craniotomy. The performance of the resistively tapered antenna is evaluated in terms of short-range sensing aspects. A series of amplitude scans along the curved array structure is proposed and measured. Three different conditions at the defect area are emulated and these images are reconstructed as a curved cranial shape.

  • 63.
    Lee, Doojin
    et al.
    UW, Mech & Mechatron Engn, Waterloo, ON, Canada.
    Shaker, George
    UW, Mech & Mechatron Engn, Waterloo, ON, Canada.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Preliminary Study: Monitoring of Healing Stages of Bone Fracture utilizing UWB Pulsed Radar Technique2018In: 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM 2018), IEEE, 2018Conference paper (Refereed)
    Abstract [en]

    The feasibility study of healing stages after fracture has been performed in this paper. The ultra-wide band (UWB) pulsed radar technique has been applied to monitor the healing stages in the way of numerical approach and simulation study as a proof of concept. The healing stages can be monitored by looking at the changes in amplitude of reflected pulse.

  • 64.
    Lee, Doojin
    et al.
    Univ Waterloo, Mech & Mechatron Engn, Waterloo, ON, Canada.
    Shaker, George
    Univ Waterloo, Mech & Mechatron Engn, Waterloo, ON, Canada.
    Nowinski, Daniel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Plastic Surgery.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Monitoring of Healing Progression of Cranial Vault using One-dimensional Pulsed Radar Technique2018In: Proceedings of the 2018 IEEE/MTT-S International Microwave Biomedical Conference (IMBioC), IEEE, 2018, p. 64-66Conference paper (Refereed)
    Abstract [en]

    In this paper, the skull healing after surgery has been investigated using proposed resistively loaded antenna utilizing the principles of short pulse radar technique. The one-dimensional pulsed profile for every stage has been demonstrated that the healing stages after craniotomy can be monitored by observing the change in the amplitude of the matched filter responses.

  • 65.
    Mathur, Parul
    et al.
    Amrita Univ, Amrita Vishwa Vidyapeetham, Amrita Sch Engn, Dept Elect & Commun Engn, Bengaluru, India.
    Kurup, Dhanesh G.
    Amrita Univ, Amrita Vishwa Vidyapeetham, Amrita Sch Engn, Dept Elect & Commun Engn, Bengaluru, India.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Design of Open Ended Circular Waveguide for Non-Invasive Monitoring of Cranial Healing in Pediatric Craniosynostosis2017In: 2017 First IEEE MTT-S International Microwave Bio Conference (IMBIOC), IEEE , 2017Conference paper (Refereed)
    Abstract [en]

    This article deals with design parameters of open ended circular waveguide (OECW) for non-invasive monitoring of skull healing in pediatric craniosynostosis patients post cranial surgery. The surgery involves removal of one or a set of bone flaps from the patient's skull. The defect thus created is filled with bone dust and heals by itself over time but complications like non-unions could occur, thereby, necessitating regular monitoring of the healing process. In this article, results of the simulated interaction of the waveguide with the skull healing are presented. Extensive optimization process is performed to arrive at optimal design parameters of the waveguide. Frequency of operation and the material that fills the waveguide are investigated to improve the sensitivity of detection and enhance the monitoring of three different stages of cranial healing.

  • 66.
    Mathur, Parul
    et al.
    Amrita Vishwa Vidyapeetham, Amrita Sch Engn, Dept Elect & Commun Engn, Bengaluru, India.
    Kurup, Dhanesh G.
    Amrita Vishwa Vidyapeetham, Amrita Sch Engn, Dept Elect & Commun Engn, Bengaluru, India.
    Perez, Mauricio D.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Mohd Shah Redzwan, Syaiful
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Velander, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    An Efficient Method for Computing the Interaction of Open Ended Circular Waveguide with a Layered Media2018In: Progress In Electromagnetics Research Letters, ISSN 1937-6480, Vol. 76, p. 55-61Article in journal (Refereed)
    Abstract [en]

    This article presents a new method for studying the near-field electromagnetic interaction between a dielectric filled open ended circular waveguide (OECW) and a layered dielectric structure. The proposed model is based on plane wave spectrum theory using a novel and computationally efficient two step integration method. The first integral, involving multiple singularities in the integration path, is efficiently solved using a deformed elliptical integration path which encircles the singularities of the integral. The infinite domain tail integral involving the slowly converging integrand is further solved using an efficient trigonometric transformation. The proposed OECW based method is capable of determining the unknown material properties of any layered dielectric medium, and hence finds application in nondestructive evaluation of materials.

  • 67.
    Mathur, Parul
    et al.
    Amrita Vishwa Vidyapeetham, RF & Wireless Syst Lab, Dept Elect & Commun Engn, Sch Engn, Bengaluru, India.
    Perez, Mauricio D.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Kurup, Dhanesh G.
    Amrita Vishwa Vidyapeetham, RF & Wireless Syst Lab, Dept Elect & Commun Engn, Sch Engn, Bengaluru, India.
    NDECOAX: A software package for nondestructive evaluation of stratified dielectric media2019In: SoftwareX, E-ISSN 2352-7110, Vol. 9, p. 187-192Article in journal (Refereed)
    Abstract [en]

    This article presents a software package based on the C++ language for accurate computation of material properties of a stratified media using an open ended coaxial probe (OECP). Since OECP is one of the most commonly used sensors for evaluation of materials today, the program developed can be customized for real time nondestructive evaluation of materials. The main contribution of this article is a computationally efficient software for solving an infinite domain integral with multiple singularities based on plane wave spectrum theory. The computed results for aperture admittance of the coaxial probe using the developed software show good agreement with both measurements and results from a commercial solver using the finite element method (FEM). It is also proved that, the execution time per frequency point of the developed code is much faster than FEM. (C) 2019 The Authors. Published by Elsevier B.V.

  • 68.
    Meaney, Paul M.
    et al.
    Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA;Chalmers Univ Technol, Dept Elect Engn, Gothenburg, Sweden.
    Geimer, Shireen D.
    Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Paulsen, Keith D.
    Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA.
    Quasi- Open-Ended Coaxial Dielectric Probe Array for Skin Burn Characterization2019In: 2019 13th European Conference On Antennas And Propagation (EUCAP), IEEE , 2019Conference paper (Refereed)
    Abstract [en]

    We have developed a planar probe for measuring dielectric properties. It exploits modern circuit board fabrication technologies that effectively construct a quasi-coaxial structure running perpendicular to the board. The feed line is a printed coplanar waveguide which comes in from the side on the top plane. The opening to the bottom behaves exactly like an open-ended coaxial probe. The initial results are comparable to the existing coaxial probes. The geometry of these probes allows them to be fabricated in an array utilizing standard, multi-layer circuit fabrication technology. These probe arrays may prove extremely useful in applications such as tumor margin detection for resected tissue, skin cancer screening and characterizing burns.

  • 69.
    Peng, Jianhui
    et al.
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Peng, Zhiwei
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Zhu, Zhongping
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Mahmoud, Morsi M.
    King Fahd Univ Petr & Minerals, Dept Mech Engn, Dhahran 31261, Saudi Arabia.
    Tang, Huimin
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Rao, Mingjun
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Zhang, Yuanbo
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Li, Guanghui
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Jiang, Tao
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Achieving ultra-high electromagnetic wave absorption by anchoring Co0.33Ni0.33Mn0.33Fe2O4 nanoparticles on graphene sheets using microwave-assisted polyol method2018In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 44, no 17, p. 21015-21026Article in journal (Refereed)
    Abstract [en]

    The Co0.33Ni0.33Mn0.33Fe2O4/graphene nanocomposite for electromagnetic wave absorption was successfully synthesized from metal chlorides solutions and graphite powder by a simple and rapid microwave-assisted polyol method via anchoring the Co0.33Ni0.33Mn0.33Fe2O4 nanoparticles on the layered graphene sheets. The Fe3+, Co2+, Ni2+ and Mn2+ ions in the solutions were attracted by graphene oxide obtained from graphite and converted to the precursors Fe(OH)(3), Co(OH)(2), Ni(OH)(2), and Mn(OH)(2) under slightly alkaline conditions. After the transformations of the precursors to Co-Ni-Mn ferrites and conversion of graphene oxide to graphene under microwave irradiation at 170 degrees C in just 25 min, the Co0.33Ni0.33Mn0.33Fe2O4/graphene nanocomposite was prepared. The composition and structure of the nanocomposite were characterized by X-ray diffraction (XRD), inductive coupled plasma emission spectroscopy (ICP), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (RS), transmission electron microscopy (TEM), etc. It was found that with the filling ratio of only 20 wt% and the thickness of 2.3 mm, the nanocomposite showed an ultra-wide effective absorption bandwidth (less than -10 dB) of 8.48 GHz (from 9.52 to 18.00 GHz) with the minimum reflection loss of - 24.29 dB. Compared to pure graphene sheets, Co0.33Ni0.33Mn0.33Fe2O4 nano particles and the counterparts reported in literature, the nanocomposite exhibited much better electromagnetic wave absorption, mainly attributed to strong wave attenuation, as a result of synergistic effects of dielectric loss, conductive loss and magnetic loss, and to good impedance matching. In view of its thin thickness, light weight and outstanding electromagnetic wave absorption property, the nanocomposite could be used as a very promising electromagnetic wave absorber.

  • 70.
    Peng, Zhiwei
    et al.
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Tang, Huimin
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Le, Joonho
    Korea Univ, Dept Mat Sci & Engn, Seoul 02841, South Korea.
    Tian, Weiguang
    Guangdong Guangqing Met Technol Co Ltd, Yangjiang 529500, Guangdong, Peoples R China.
    Chen, Yanhu
    Guangdong Guangqing Met Technol Co Ltd, Yangjiang 529500, Guangdong, Peoples R China.
    Gu, Foquan
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Zhang, Yuanbo
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Li, Guanghui
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    Jiang, Tao
    Cent S Univ, Sch Minerals Proc & Bioengn, Changsha 410083, Hunan, Peoples R China.
    From ferronickel slag to value-added refractory materials: A microwave sintering strategy2019In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 149, p. 521-531Article in journal (Refereed)
    Abstract [en]

    The present study proposes a novel strategy for preparation of refractory materials from potentially hazardous ferronickel slag by microwave sintering of the slag with addition of sintered magnesia in which a series of chemical reactions were involved. This strategy was developed based on examination of the phase transformations and microstructural changes of the slag during microwave sintering through X-ray diffraction (XRD) analysis and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) analysis, which determined the properties of refractory materials derived from the slag. It was shown that under microwave irradiation there existed rapid transformation of the olivine phase in the slag to high-melting point phases, including forsterite and spinels (e.g., magnesium iron chromate spinel, magnesium chromate spinel, and magnesium iron aluminate spinel). As a result, a high-quality refractory material with refractoriness of 1730 degrees C, bulk density of 2.80 g/cm(3), apparent porosity of 1.6%, and compressive strength of 206.62 MPa was obtained by microwave sintering of the slag at 1350 degrees C for only 20 min with addition of 25 wt % sintered magnesia. Because the microwave sintering strategy not only elevated the refractoriness by 70 degrees C, but also reduced the heating duration required by the conventional approach by 6 times, it demonstrated apparent technological superiority and wide application prospect in preparing superior-quality refractory materials from ferronickel slag and relevant industrial waste, which contributed to conservation of resources and energy as well as environmental protection.

  • 71.
    Perez, Mauricio D.
    et al.
    Natl Technol Univ, Mendoza Reg Fac, Dept Elect, Electrostat & Dielect Mat Lab, Buenos Aires, DF, Argentina..
    Redzwan, Syaiful Mohd Shah
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Velander, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Raaben, Marco
    UMC Utrecht, Surg, Traumatol, Heidelberglaan 100, NL-3584 CX Utrecht, Netherlands..
    Asan, Noor Badariah
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Blokhuis, Taco
    Maastricht Univ, Med Ctr, Traumatol Dept, Maastricht, Netherlands..
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Microwave Sensors for New Approach in Monitoring Hip Fracture Healing2017In: 2017 11th European Conference On Antennas And Propagation (EUCAP), IEEE , 2017, p. 1838-1842Conference paper (Refereed)
    Abstract [en]

    Cyber-Physical System (CPS) applications in lower-extremity bony-fracture rehabilitation systems require real-time biophysical data. Emerging and interesting solutions are microwave approaches that provide good contrast between hard and soft tissues and between local anomalies inside tissues. Preliminarily some contacting non-invasive planar methods have been investigated in their feasibility of detecting human tissues variations with promising results. In this work we introduce two new microwave planar sensors for a new approach of hip fracture healing follow-up tool. They are designed for improved resolution and penetration at frequencies between 1 to 3 GHz in detecting variations in bone, muscle or fat tissues that are expected during a rehabilitation process. The resonant devices are optimized using Frequency Domain Reflectometry and CST (R) environment and validated using clinical trials with volunteers. The new approach is validated using clinical trials with volunteers and patients. These outcomes further emphasize the feasibility of devising systems for fracture rehabilitation.

  • 72.
    Raaben, Marco
    et al.
    Univ Med Ctr Utrecht, Dept Surg, Heidelberglaan 100, NL-3584 CX Utrecht, Netherlands.
    Holtslag, Herman R.
    Acad Med Ctr Amsterdam, Dept Rehabil Med, Meibergdreef 9, NL-1105 AZ Amsterdam, Netherlands.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    van Merkerk, Rutger O.
    Univ Med Ctr Utrecht, Pontes Med, Heidelberglaan 100, NL-3584 CX Utrecht, Netherlands.
    Koopman, Bart F. J. M.
    Univ Twente, Dept Biomech Engn, Drienerlolaan 5, NL-7522 NB Enschede, Netherlands.
    Blokhuis, Taco J.
    Maastricht Univ, Dept Surg, Med Ctr, P Debyelaan 25, NL-6229 HX Maastricht, Netherlands.
    Technical Aspects and Validation of a New Biofeedback System for Measuring Lower Limb Loading in the Dynamic Situation2017In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 17, no 3, article id 658Article in journal (Refereed)
    Abstract [en]

    Background: A variety of techniques for measuring lower limb loading exists, each with their own limitations. A new ambulatory biofeedback system was developed to overcome these limitations. In this study, we described the technical aspects and validated the accuracy of this system. Methods: A bench press was used to validate the system in the static situation. Ten healthy volunteers were measured by the new biofeedback system and a dual-belt instrumented treadmill to validate the system in the dynamic situation. Results: Bench press results showed that the sensor accurately measured peak loads up to 1000 N in the static situation. In the healthy volunteers, the load curves measured by the biofeedback system were similar to the treadmill. However, the peak loads and loading rates were lower in the biofeedback system in all participants at all speeds. Conclusions: Advanced sensor technologies used in the new biofeedback system resulted in highly accurate measurements in the static situation. The position of the sensor and the design of the biofeedback system should be optimized to improve results in the dynamic situation.

  • 73.
    Raaben, Marco
    et al.
    Univ Med Ctr Utrecht, Dept Surg, Heidelberglaan 100, NL-3508 GA Utrecht, Netherlands..
    Holtslag, Herman R.
    Acad Med Ctr, Dept Rehabil Med, Meibergdreef 9, NL-1105 AZ Amsterdam, Netherlands..
    Leenen, Luke P. H.
    Univ Med Ctr Utrecht, Dept Surg, Heidelberglaan 100, NL-3508 GA Utrecht, Netherlands..
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Blokhuis, Taco J.
    Maastricht Univ, Dept Surg, Med Ctr, P Debyelaan 25, NL-6229 HX Maastricht, Netherlands..
    Real-time visual biofeedback during weight bearing improves therapy compliance in patients following lower extremity fractures2018In: Gait & Posture, ISSN 0966-6362, E-ISSN 1879-2219, Vol. 59, p. 206-210Article in journal (Refereed)
    Abstract [en]

    Background: Individuals with lower extremity fractures are often instructed on how much weight to bear on the affected extremity. Previous studies have shown limited therapy compliance in weight bearing during rehabilitation. In this study we investigated the effect of real-time visual biofeedback on weight bearing in individuals with lower extremity fractures in two conditions: full weight bearing and touch-down weight bearing. Methods: 11 participants with full weight bearing and 12 participants with touch-down weight bearing after lower extremity fractures have been measured with an ambulatory biofeedback system. The participants first walked 15 m and the biofeedback system was only used to register the weight bearing. The same protocol was then repeated with real-time visual feedback during weight bearing. The participants could thereby adapt their loading to the desired level and improve therapy compliance. Results: In participants with full weight bearing, real-time visual biofeedback resulted in a significant increase in loading from 50.9 +/- 7.51% bodyweight (BW) without feedback to 63.2 +/- 6.74% BW with feedback (P=0.0016). In participants with touch-down weight bearing, the exerted lower extremity load decreased from 16.7 +/- 9.77 kg without feedback to 10.27 +/- 4.56 kg with feedback (P=0.0718). More important, the variance between individual steps significantly decreased after feedback (P=0.018). Conclusions: Ambulatory monitoring weight bearing after lower extremity fractures showed that therapy compliance is low, both in full and touch-down weight bearing. Real-time visual biofeedback resulted in significantly higher peak loads in full weight bearing and increased accuracy of individual steps in touch-down weight bearing. Real-time visual biofeedback therefore results in improved therapy compliance after lower extremity fractures.

  • 74.
    Raaben, Marco
    et al.
    Univ Med Ctr Utrecht, Dept Surg, Heidelberglaan 100, NL-3508 GA Utrecht, Netherlands.
    Mohd Shah, Syaiful Redzwan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Blokhuis, Taco Johan
    Maastricht Univ, Med Ctr, Dept Surg, P Debyelaan 25, NL-6229 HX Maastricht, Netherlands.
    COMplex Fracture Orthopedic Rehabilitation (COMFORT) - Real-time visual biofeedback on weight bearing versus standard training methods in the treatment of proximal femur fractures in the elderly: study protocol for a multicenter randomized controlled trial2018In: Trials, ISSN 1745-6215, E-ISSN 1745-6215, Vol. 19, article id 220Article in journal (Refereed)
    Abstract [en]

    Background:

    Proximal femur fractures are a common injury after low energy trauma in the elderly. Most rehabilitation programs are based on restoring mobility and early resumption of weight-bearing. However, therapy compliance is low in patients following lower extremity fractures. Moreover, little is known about the relevance of gait parameters and how to steer the rehabilitation after proximal femur fractures in the elderly. Therefore, the aim of this prospective, randomized controlled trial is to gain insight in gait parameters and evaluate if real-time visual biofeedback can improve therapy compliance after proximal femur fractures in the elderly.

    Methods:

    This is a two-arm, parallel-design, prospective, randomized controlled trial. Inclusion criteria are age >= 60 years, a proximal femur fracture following low energy trauma, and unrestricted-weight bearing. Exclusion criteria are cognitive impairment and limited mobility before trauma. Participants are randomized into either the control group, which receives care as usual, or the intervention group, which receives real-time visual biofeedback about weight-bearing during gait in addition to care as usual. Spatiotemporal gait parameters will be measured in 94 participants per group during a 30-m walk with an ambulatory biofeedback system (SensiStep). The progress of rehabilitation will be evaluated by the primary outcome parameters maximum peak load and step duration in relation to the discharge date. Secondary outcome parameters include other spatiotemporal gait parameters in relation to discharge date. Furthermore, the gait parameters will be related to three validated clinical tests: Elderly Mobility Scale; Functional Ambulation Categories; and Visual Analogue Scale. The primary hypothesis is that participants in the intervention group will show improved and faster rehabilitation compared to the control group.

    Discussion:

    The first aim of this multicenter trial is to investigate the normal gait patterns after proximal femur fractures in the elderly. The use of biofeedback systems during rehabilitation after proximal femur fractures in the elderly is promising; therefore, the second aim is to investigate the effect of real-time visual biofeedback on gait after proximal femur fractures in the elderly. This could lead to improved outcome. In addition, analysis of the population may indicate characteristics of subgroups that benefit from feedback, making a differentiated approach in rehabilitation strategy possible.

  • 75.
    Raman, Sujith
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Dancila, Dragos
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Gain enhancement and radiation pattern reconfiguration for microstrip planar Yagi-Uda antenna2014Conference paper (Refereed)
  • 76.
    Raman, Sujith
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Geometrical and Dimensional Dependance of Skull Implants on Oseointegration Analysis Using Microwave Probe2014In: 2014 IEEE CONFERENCE ON ANTENNA MEASUREMENTS & APPLICATIONS (CAMA), 2014Conference paper (Refereed)
    Abstract [en]

    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.

  • 77.
    Raman, Sujith
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University.
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Osseointegration analysis of skull implants using microstrip fed split ring resonator antenna2014In: 2014 XXXITH URSI General Assembly And Scientific Symposium (URSI GASS), 2014Conference paper (Refereed)
    Abstract [en]

    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.

  • 78.
    Redzwan Mohd Shah, Syaiful
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. Uppsala University.
    Velander, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Perez, Mauricio D.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Joseph, Laya
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Mattsson, Viktor
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Asan, Noor Badariah
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Huss, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Plastic Surgery.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Improved Sensor for Non-invasive Assessment of Burn Injury Depth Using Microwave Reflectometry2019In: 2019 13th European Conference on Antennas and Propagation (EuCAP), 2019Conference paper (Refereed)
    Abstract [en]

    The European project “Senseburn” aims to develop a non-invasive diagnostic instrument for assessing the depth and propagation of human burns in the clinical scenario. This article introduces an improved flexible microwave split-ring resonator-based sensor, as a new development in this project. The excitation system and the fabrication process are the major improvements with respect to its precedent microwave sensor, both based in polydimethylsiloxane (PDMS) and copper. Both improvements are introduced together with the design of the sensor and of the experimental setup. Human tissue emulating phantoms are designed, fabricated, validated, and employed to emulate different burn depths and to validate the conceptual functionality of the proposed sensor. The Keysight dielectric probe 85070E is employed for the phantom validation. The analysis suggests that the sensor could estimate the burn depth. Future works will be carried out with ex vivo human tissues. 

  • 79.
    Redzwan, Syaiful
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Asan, Noor Badariah
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. Univ Teknikal Malaysia Melaka, Fac Elect & Comp Engn, Durian Tunggal 76100, Malaysia.
    Velander, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Ebrahimizadeh, Javad
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Perez, Mauricio D.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Mattsson, Viktor
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Blokhuis, Taco J.
    Maastricht Univ, Traumatol Dept, Med Ctr, NL-6229 HX Maastricht, Netherlands.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Analysis of Thickness Variation in Biological Tissues using Microwave Sensors for Health Monitoring Applications2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 156033-156043Article in journal (Refereed)
    Abstract [en]

    Microwave sensing technique is a possible and attractive alternative modality to standard Xrays,magnetic resonance imaging, and computed tomography methods for medical diagnostic applications.This technique is beneficial since it uses non-ionizing radiation and that can be potentially used for themicrowave healthcare system. The main purpose of this paper is to present a microwave sensing techniqueto analyze the variations in biological tissue thickness, considering the effect of physiological and biologicalproperties on microwave signals. With this goal, we have developed a two-port non-invasive sensor systemcomposed of two split ring resonators (SRRs) operating at an Industrial, Scientific, and Medical frequencyband of 2.45 GHz. The system is verified using the amplitude and phase of the transmitted signal in ex-vivomodels, representing different tissue thicknesses. Clinical applications such as the diagnosis of muscularatrophy can be benefitted from this study.

  • 80.
    Redzwan, Syaiful
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Velander, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Mathur, Parul
    Amrita Vishwa Vidyapeetham, Amrita Sch Engn, Dept Elect & Commun, Bengaluru 560035, India.
    Perez, Mauricio D.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Asan, Noor Badariah
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Kurup, Dhanesh G.
    Amrita Vishwa Vidyapeetham, Amrita Sch Engn, Dept Elect & Commun, Bengaluru 560035, India.
    Blokhuis, Taco J.
    Maastricht Univ, Med Ctr, Dept Surg, POB 5800, NL-6202 AZ Maastricht, Netherlands.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Split-Ring Resonator Sensor Penetration Depth Assessment Using In Vivo Microwave Reflectivity and Ultrasound Measurements for Lower Extremity Trauma Rehabilitation2018In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 18, no 2, article id 636Article in journal (Refereed)
    Abstract [en]

    In recent research, microwave sensors have been used to follow up the recovery of lower extremity trauma patients. This is done mainly by monitoring the changes of dielectric properties of lower limb tissues such as skin, fat, muscle, and bone. As part of the characterization of the microwave sensor, it is crucial to assess the signal penetration in in vivo tissues. This work presents a new approach for investigating the penetration depth of planar microwave sensors based on the Split-Ring Resonator in the in vivo context of the femoral area. This approach is based on the optimization of a 3D simulation model using the platform of CST Microwave Studio and consisting of a sensor of the considered type and a multilayered material representing the femoral area. The geometry of the layered material is built based on information from ultrasound images and includes mainly the thicknesses of skin, fat, and muscle tissues. The optimization target is the measured S-11 parameters at the sensor connector and the fitting parameters are the permittivity of each layer of the material. Four positions in the femoral area (two at distal and two at thigh) in four volunteers are considered for the in vivo study. The penetration depths are finally calculated with the help of the electric field distribution in simulations of the optimized model for each one of the 16 considered positions. The numerical results show that positions at the thigh contribute the highest penetration values of up to 17.5 mm. This finding has a high significance in planning in vitro penetration depth measurements and other tests that are going to be performed in the future.

  • 81.
    Redzwan, Syaiful
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Velander, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Perez, Mauricio D.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Asan, Noor Badariah
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Rajabi, Mina
    KTH Royal Inst Technol, Sch Elect Engn, Dept Micro & Nanosyt, Stockholm, Sweden.
    Niklaus, Frank
    KTH Royal Inst Technol, Sch Elect Engn, Dept Micro & Nanosyt, Stockholm, Sweden.
    Nowinski, Daniel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Plastic Surgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Initial In-Vitro Trial for Intra-Cranial Pressure Monitoring Using Subdermal Proximity-Coupled Split-Ring Resonator2018In: Proceedings of the 2018 IEEE/MTT-S International Microwave Biomedical Conference (IMBioC), IEEE, 2018, p. 73-75Conference paper (Refereed)
    Abstract [en]

    Intra cranial pressure (ICP) monitoring is used in treating severe traumatic brain injury (TBI) patients. All current clinical available measurement methods are invasive presenting considerable social costs. This paper presents a preliminary investigation of the feasibility of ICP monitoring using an innovative microwave-based non-invasive approach. A phantom mimicking the dielectric characteristics of human tissues of the upper part of the head at low microwave frequencies is employed together to a proof-of-concept prototype based on the proposed approach consisting in a readout system and a sub-dermally implanted passive device, both based in split ring resonator techniques. This study shows the potential of our approach to detect two opposite pressure variation stages inside the skull. The employed phantom model needs to be improved to support finer variations in the pressure and better phantom parts, principally for the skull mimic and the loss tangent of all mimics.

  • 82.
    Rydberg, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Grudén, Mathias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Jobs, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Dancila, Dragos
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Research on wireless sensors networks for electro-magnetically and physically hostile environments2014Conference paper (Refereed)
  • 83. Töpfer, Fritzi
    et al.
    Dudorov, Sergey
    Dancila, Dragos
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Hu, Xin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Emtestam, Lennart
    Gustafsson, Kari
    Tenerz, Lars
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Oberhammer, Joachim
    A micromachined millimeter-wave sensor for skin-cancer diagnosis2013Conference paper (Refereed)
  • 84.
    Töpfer, Fritzi
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. Micro and Nanosystems, KTH Royal Institute of Technology, Stockholm, Sweden.
    Dudorov, Sergey
    Dancila, Dragos
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Hu, Xin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Emtestam, Lennart
    Tenerz, Lars
    Oberhammer, Joachim
    Micromachined near-field millimeter-wave medical sensor for skin cancer diagnosis2013Conference paper (Refereed)
    Abstract [en]

    This paper presents the recent achievements in a project on micromachined millimeter-wave near-field medical sensors, in particular for skin cancer diagnosis. Micromachining enables sensor probes which achieve both hig sensitivity and high lateral resolution through a drastically miniaturized probe tip. Two different design strategies are investigated: a broad-band, non-resonating, tapered dielectric-rod probe, and a resonance slot sensor. For probe characterization micromachined silicon test and calibration samples with tailor-made permittivity were fabricated. Characterization of fabricated prototypes show that the tapered probe can clearly and reproducibly distinguish .....

  • 85. Töpfer, Fritzi
    et al.
    Dudorov, Sergey
    Dancila, Dragos
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Emtestam, Lennart
    Tenerz, Lars
    Oberhammer, Joachim
    High-resolution microwave skin cancer diagnostic tool based on micromachined interface2012Conference paper (Refereed)
  • 86.
    Velander, Jacob
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Redzwan, Syaiful
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Perez, Mauricio D.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Asan, Noor Badariah
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Nowinski, Daniel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Plastic Surgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    A Four-Layer Phantom for Testing In-Vitro Microwave-Based Sensing Approach in Intra-Cranial Pressure Monitoring2018In: Proceedings Of The 2018 IEEE/MTT-S International Microwave Biomedical Conference (IMBioC), IEEE, 2018, p. 49-51Conference paper (Refereed)
    Abstract [en]

    Multi-layer phantoms in proofs of concept, designs and validations of both microwave-based biomedical sensing and imaging system are becoming popular means to facilitate in-vitro experiments. In addition, they can contribute significantly to reduce animal use in scientific experimentation. In this paper, we design and fabricate a four-layer phantom composed of skin, skull, cerebrospinal fluid and brain mimic tissues to work between 2 and 3 GHz. In addition, the phantom incorporates a mechanism to produce pressure variation between the cerebrospinal fluid and the brain mimic tissues. This phantom is used in an in-vitro experiment to test and validate a new approach which could sense intra-cranial pressure variations through a microwave-based reflection method. The similarity of the phantom's tissues with human tissues from the viewpoint of the microwave response is analyzed in comparison with data from Italian Institute of Applied Physics in Florence. We found good agreement for the dielectric constant (Rel. Err. < 13 % for 68% of significance) in skin, cerebrospinal fluid and brain mimic tissues. For the skin, we got also good agreement for the loss tangent (Rel. Err. < 11 % for 68% of significance). The skull mimic phantom was stiff enough, but even presenting considerable errors, it was still good enough for the experiment. In addition, the capability of the phantom to operate at different pressures is discussed.

  • 87.
    Voigt, Thiemo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Asan, Noor Badariah
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Perez, Mauricio D.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Ahlén, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Signals and Systems Group.
    Teixeira, André
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Signals and Systems Group.
    Hylamia, Sam
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Rohner, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Yan, Wenqing
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Joseph, Laya
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Mani, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Plastic Surgery.
    LifeSec - Don’t Hack my Body2019Conference paper (Refereed)
  • 88.
    Voigt, Thiemo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Augustine, Robin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Asan, Noor Badariah
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Perez, Mauricio D.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Ahlén, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Signals and Systems Group.
    Teixeira, André
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Signals and Systems Group.
    Hylamia, Sam
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Rohner, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Yan, Wenqing
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Joseph, Laya
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Mani, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Plastic Surgery.
    Tumor Sensing Privacy in In-Body Networks2019Conference paper (Refereed)
12 51 - 88 of 88
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