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  • 1.
    Ahmed, Mobyen Uddin
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Begum, Shahina
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Kerstis, Birgitta
    Mälardalens högskola, Akademin för hälsa, vård och välfärd, Hälsa och välfärd.
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Sandborgh, Maria
    Mälardalens högskola, Akademin för hälsa, vård och välfärd, Hälsa och välfärd.
    Third Eye: An Intelligent Assisting Aid for Visual Impairment Elderly2016Inngår i: Medicinteknikdagarna 2016 MTF, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Background Visually impaired older persons need support in daily activities, e.g. moving around inside the house; making and eating food and taking medicine independently. A system that simulates the environment based on both dynamic and static objects, identify obstacles, navigates and translates sensory information in voice would be valuable to support their daily activities. Today several sensors and camera-based systems are popular as ambient-assisted living tools for older adults. However, intelligent assisting aid (IAA) to support older individuals with a recently acquired visual impairment is limited. The proposed system ‘Third Eye’ focuses on the advanced research and development of an IAA to support older individuals with a recently acquired visual impairment. The main goal in this system is to provide a usable, feasible and cost-effective solution for older persons to support their daily activities using intelligent sensor based system. Method The system consists of the following five phases to meet several central challenges in developing IAA in such domain. • User-perspective, focuses on user-driven technical development, investigating needs of potential users. The study will have a participatory design with focus group interviews of lead users. • Sensor-based system, focuses on the identification obstacles based on ultrasounds and/or radio frequencies embedded in white-cane or weaker. • Camera-based system, focuses on image based information translation into voice embedded in white-cane or weaker or glasses. • System of systems, focuses on integration of above systems where knowledge is engineered and suitable representations are learned and reasoning for decisions are made [9]. • Experimental, focuses on usability and feasibility of the IAA, with idiographic and group studies Results The initial results have shown the necessity of the proposed AAI systems for older individuals with a recently acquired visual impairment. However, more extension work e.g., process and analyze the information and synthesize it with existing literature for developing the system is ongoing.

  • 2.
    Fotouhi, Hossein
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Vahabi, Maryam
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Tomasic, Ivan
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. ES (Embedded Systems).
    IPv6 connectivity in eHealth IoT networks2018Inngår i: Medicinteknikdagarna 2018 MTD 2018, Umeå, Sweden, 2018Konferansepaper (Fagfellevurdert)
  • 3.
    Hozhabri, Melika
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Petrović, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ekström, Martin
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Experimental Comparison Study of UWB Technologies for Static Human Detection2016Inngår i: IEEE International Conference on Ubiquitous Wireless Broadband (ICUWB 2016) ICUWB 2016, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper compares two dominant Ultra Wide Rand(UWB) radar technologies Impulse and M-sequence for static human being detection in free space. The hardware and software platform for each system is described separately. These two radar platform performances are tested in real conditions and the results show that M-sequence UWB radar is better suited for detecting the static human target in larger distances.

  • 4.
    Hozhabri, Melika
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Comparison of UWB Radar Back-Scattering by the Human Torso and a Phantom2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An Ultra Wide Band(UWB) radar is used to measure the cross section of a human phantom indifferent polarizations of the receiver antenna. The choice of material and shape for the human phantom is discussed. The material used in the experiment(wet sand) dielectric properties measured by a retromodeling technique and then calculated by mixture formulas. The appropriate frequency choice for the application is discussed.

  • 5.
    Hozhabri, Melika
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Study of the Environment Effect by M-Sequence UWB Radar on Detection of a Walking Human2016Inngår i: 2016 IEEE Conference on Antenna Measurements & Applications (CAMA) CAMA 2016, 2016, artikkel-id 7815740Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents an experimental comparison study of human movement and presence detection in different environments using ultra-wide-band (UWB) M-Sequence radar. The benchmarking measurements are made in an anechoic chamber and repeated in an open office environment. The wave forms of the background noise and scattered amplitudes of a human body are measured and compared. The result is analyzed and discussed. A set of detection algorithms and filters which are developed to track the human movement and presence is presented and the tracking results in these two environments are compared to each other.

  • 6.
    Otterskog, Magnus
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    A multi-layered head phantom for microwave investigations of brain hemorrhages2016Inngår i: 2016 IEEE Conference on Antenna Measurements & Applications (CAMA) CAMA 2016, Syracuse, United States, 2016, artikkel-id 7815764Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A head phantom for microwave investigations is developed. It consists of a skull bone with realistic dielectric properties of cancellous and cortical bone. The skull phantom is filled with liquids and semi-solids that dielectrically represent the white/gray matter and blood, respectively.

  • 7.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Fotouhi, Hossein
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Tomasic, Ivan
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A remote health monitoring system featuring relational databases2017Inngår i: Medicinteknikdagarna 2017 MTD 2017, Västerås, Sweden, 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Remote health monitoring (RHM) through the use of wearable wireless sensors, has drawn a lot of attention from academia and industry in the last decade [1,2]. The aging population, increasing cost of health-care, and lack of human resources in healthcare, are the three key motivators for the development of RHM [3,4]. The RHM systems should reduce health care costs and improve care quality. How to ensure a reliable and secure data collection from sensor devices to stake holders in RHM systems, is an open research question. The most established data storage technology that can ensure the security and privacy of data is the relational database management systems (RDBMSs). Besides security, RDBMSs provide a number of additional convenient features like querying the data, indexing, backups, replication, but are however in general slower than storing the data directly in a file system. Presented is a RHM system with a RDBMS in its core. The system was developed for the needs of ESS-H research profile [5] at Mälardalen University, Sweden. We also present a comprehensive system design which covers all the needs for the RHM application. The system is composed of four main components: (I) Shimmer sensors [6], (II) data acquisition layer (LabVIEW or C#.NET program), (III) RDBMS, and (IV) web service and web interface. The system communicates with the Shimmer sensors over Bluetooth and collects measurements in a relational database, either through a C#.NET or a LabVIEW program. The web service and a web interface are both written in PHP and are running on the Apache HTTP Server. The end-user is able to observe either real-time data (i.e. with insignificant delay) or processed historical data on any web browser. The advantage of using the web interface instead of a desktop application is that it makes the presentation layer easily accessible and platform independent. The RDBMSs provide data security and privacy in addition to other convenient features. Therefore, it is beneficial to incorporate RDBMSs in RHM systems. However, the RDBMSs provide no solution for security and privacy issues in wireless communication which is another research problem.

  • 8.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Gunnarsson, Tommy
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Joachimowicz, Nadine
    L2S/ Supélec/Universite Paris-Sud 11.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Robot Controlled Data Acquisition System for Microwave Imaging2009Inngår i: 3rd European Conference on Antennas and Propagation, 2009, , s. 5s. 3240-3244Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper an experimental prototype of a robot controlled data acquisition system for microwave imaging is presented, where the transmitting and receiving antennas are immersed in a water-tank. The scattered field from the object under test is acquired by using the robot and scanning a single receiving antenna in cylindrical or half spherical coordinates, while the transmitting antenna is fixed at one position with possibilities to be manually moved to different positions. Careful design and construction of the system has given accurate measurements of incident and total field with a SNR of 45dB. A validation of the robot system is performed by comparing measured and computed data for a sunflower oil object.In this paper an experimental prototype of a robot controlled data acquisition system for microwave imaging is presented, where the transmitting and receiving antennas are immersed in a water-tank. The scattered field from the object under test is acquired by using the robot and scanning a single receiving antenna in cylindrical or half spherical coordinates, while the transmitting antenna is fixed at one position with possibilities to be manually moved to different positions. Careful design and construction of the system has given accurate measurements of incident and total field with a SNR of 45dB. A validation of the robot system is performed by comparing measured and computed data for a sunflower oil object.

  • 9.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Henriksson (Gunnarsson), Tommy
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Antenna Modeling Issues in Quantitative Image Reconstruction Using a Flexible Microwave Tomography System2010Inngår i: PIERS 2010 CAMBRIDGE: PROGRESS IN ELECTROMAGNETICS RESEARCH SYMPOSIUM PROCEEDINGS, 2010, s. 952-956Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Quantitative microwave imaging has been extensively studied in the past years as an alternative technique in biomedical imaging, with a strong potential in early stage breast can- cer detection [Keith D. Paulsen and Paul M. Meaney, \Alternative Breast Imaging", The Springer International Series in Engineering and Computer Science, 778, 2005]. The image reconstruction involves a nonlinear inverse scattering problem, which consists to retrieve the dielectric prop- erties of the biological object from the measured scattered field, for an applied incident field. Consequently, the solution is highly sensitive to model errors in the incident field. This paper focus on the impact of this model error on the reconstructed quantitative image using a °exible robotic microwave imaging system, developed at MAalardalen University, together with an itera- tive Newton-Kantorovich (NK) algorithm. This study is conducted during the development of the imaging system and the first quantitative images of a breast phantom are obtained. The robotic microwave imaging system is developed as a °exible experimental platform for biomedical imaging, where one of the applications is breast imaging. Using a robot controlled system the scattered field can be measured with a single transmitting/receiving antenna-pair, thus avoiding the mutual coupling that occur when an antenna-array is used. The scattered field is, herein, measured around a breast phantom, along a circular arc, in the horizontal plane with vertically polarized monopole antennas, considering a two dimensional transverse magnetic case (2D-TM). The radiated field from the transmitting antenna is modeled as a vertical polarized cylindrical wave in the numerical incident field model of the NK algorithm, where images with both the real- and imaginary permittivity profile of the breast phantom are obtained. In this study, two di®erent monopole antenna designs are compared with the numerical incident field model. The di®erence between the antennas is the ground-plane design, where the first setup uses 4 wires forming a horizontal cross as a ground-plane. By varying the length of the wires and angel between the transmitting and receiving antenna the incident electromagnetic field is changed and could be modified to best fit the simulated field. The second setup uses a circular ground plane which will give a more rotational symmetric radiation pattern in the horizontal plane and a better match when comparing measured fields with computed values. The comparison is done directly with the numerical incident field model, as well as the computed and measured scattered field, and finally the impact on the reconstructed images by the NK algorithm are compared, using measured data from both antennas. The results show how the antenna selection impacts the error between the measured incident field and the numerical model, and how the quantitative image of an inhomogeneous object is a®ected by this model error.

  • 10.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Permittivity Measurements with a Resonant Cavity to Develop Human Tissue Phantoms for Microwave Imaging2009Inngår i: Proceedings of the 8th International Conference on Electromagnetic Wave Interaction with Water and Moist Substances (ISEMA 2009) / [ed] Pertti Vainikainen, Helsinki, 2009, s. 190-195Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In order to create human tissue phantoms for a microwave imaging system, a method to determine the complex permittivity is needed. For this reason a cavity perturbation method has been analyzed and used to perform measurements characterizing the complex permittivity of different fluid mixtures. Results show good agreement on single frequency between the measurement with the reentrant cavity and references. However the complex part of the final material mixture mimicking human tissue are higher than expected, which makes 1.2-propylene glycol inappropriate as a human tissue phantom material. The cavity perturbation method is still a suitable method for measuring liquids and with more work it might even be reliable for gel-based materials.

  • 11.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Risman, P. O.
    Microtrans AB, Sweden.
    Antenna applicator design for microwave imaging of the interior of human breasts2014Inngår i: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 47, nr 38, artikkel-id Article Number: 385401Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper we introduce a waveguide antenna applicator design intended to be placed on the surface or in close proximity to a human breast for imaging purposes. Hence, the antenna needs to be compact for easy placement. The design process is carefully carried out dividing the antenna applicator into separate parts, allowing closer analysis towards improved synthesis. A mode applicator antenna was concluded to be necessary, employing a TE10 mode type with minimized near-field and surface (Zennek) wave excitation. Numerical simulations have been used throughout and show that the proposed ridged waveguide antenna is capable of fulfilling the design requirements and the performance goals. Modelling has been carried out using a scenario with a simple breast model and confirms the applicator's capability.

  • 12.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Antenna applicator concepts using diffraction phenomena for direct visualization of brain hemorrhages2016Inngår i: 2016 IEEE Conference on Antenna Measurements & Applications (CAMA) CAMA 2016, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Direct use of diffraction phenomena at an irregularity in a lossy object such as a head is described. The source is an external magnetic field directed into the skull, creating a circulating current inside the object by which surface waves are avoided. The receiving E-field probe is a 3D resonant structure being selectively sensitive to the desired deflected electric field component from the surface.

  • 13.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Antenna Applicators and Microwave Fields for Imaging of the Interior of Human Breasts and Heads2016Konferansepaper (Annet vitenskapelig)
  • 14.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Breast tumor detection with microwave applicators in open air2017Inngår i: 2017 IEEE Conference on Antenna Measurements & Applications (CAMA) CAMA 2017, 2017, s. 272-274Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A system for either direct use of diffraction phenomena or indirect use by computational methods for female breast tumor detection is described. The excitation device is a single external non-contacting, sectioned single turn loop, creating an axial magnetic field directed into the breast. A circulating current is created inside it and the diffracted field is directly sensed.

  • 15.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Breast tumour detection by two microwave antenna principles2017Inngår i: Proceedings of the 2017 19th International Conference on Electromagnetics in Advanced Applications, ICEAA 2017, Institute of Electrical and Electronics Engineers Inc. , 2017, s. 1258-1261Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A comparison between breast tumour detection with a traditional lossy coupling medium based system and a system without coupling medium is performed, by numerical modelling and experimentally. While a system with lossy coupling medium offers surface wave reduction and protection from surrounding sources and obstacles it also demands good permittivity matching of the coupling medium to the breast tissue under investigation, as well as a high performance measurement system with a dynamic range exceeding 100 dB. The system without coupling medium offers possible direct detection of inhomogeneities with transmission losses of about 50...60 dB. The proposed contacting antenna system however needs further development in order to reduce stray fields and adoption to realistic breast tissue properties.

  • 16.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Experiments and numerical modelling of contacting antenna applicators at a free space head model2015Inngår i: 2015 IEEE International Conference on Antenna Measurements & Applications (CAMA) CAMA 2015, 2015, artikkel-id 7428125Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Microwave absorbing boluses or similar are impractical, particularly in stroke emergencies, since the creation of surface waves around the head dominating over the internal signal paths is then a problem. The performance of miniaturised ridged waveguide applicators in the frequency interval 1 to 3 GHz designed for the application of breast cancer detection are used in this study, slightly modified, on head models for investigation of disturbing surface waves.

  • 17.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    QUANTIFICATION OF INHOMOGENEITIES IN OBJECTS BY ELECTROMAGNETIC FIELDS2017Patent (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    A system and method, as well as sub assemblies thereof, for detection of dielectric irregularities/inhomogeneities inside an object under study (OUS) be means of electromagnetic energy are disclosed. The system comprises a loop/cylinder emitter configured to be located close to the OUS with its axis of symmetry directed towards the OUS. A feeding line feeds the emitter with an alternating current at an operating frequency to cause a magnetic field therein, which in turn will induce a propagating electromagnetic field in the OUS. In order to reduce propagating fields outside of the OUS, the circumference of the emitter is smaller than the free-space wavelength corresponding to the operating frequency, and the feeding line has a characteristic impedance that is smaller than 20 Ohm.

  • 18.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A Zirconia Cylindrical TM010 Cavity for Permittivity Measurements at 1 GHz2018Inngår i: 2018 IEEE CAMA Conference on Antenna Measurement and Applications CAMA 2018, 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The most accurate dielectric measurements are made by resonant cavity methods, the circular TM010 type being the simplest and most common. However, an airfilled such cavity at 1 GHz needs to be 250 mm in diameter. There is another problem as well: its limited applicability with very lossy samples, due to a too low Q value. This paper describes the development and properties of a metalized zirconia ceramic cavity for use at about 1 GHz. With its permittivity ε′ = 30 its diameter becomes 40 mm instead of 150 mm for the airfilled version. Additionally and importantly, the dynamic range of the loss factor ε″ is greatly expanded. The calibration procedure using numerical retromodelling is described and a measurement example of a ternary alcohol mixture is carried out. The accuracy is also estimated.

  • 19.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Overview of microwave based diagnostics for breast tumours and strokes2018Inngår i: World Congress on Medical Physics and Biomedical Engineering IUPESM 2018, 2018, nr 1Konferansepaper (Fagfellevurdert)
  • 20.
    Petrovic, Nikola
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Tomasic, Ivan
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Risman, Per Olov
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Detection of Human Bodypart Abnormalities by Microwaves – A New Approach2019Inngår i: 42nd International Convention on Information and Communication Technology, Electronics and Microelectronics MIPRO 2019, 2019, s. 270-274Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present modified antenna-like devices - applicators - for direct detection of internal inhomogeneities such as breast tumours and brain haemorrhages, at a frequency about 1 GHz. This direct detection provides the possibility of using a simple microwave generator and simple rectification and position registration of the received signals. Direct readouts are thus possible, without any massive computing resources as with tomographic imaging. The transmitting applicator is non-contacting and in free air close to the object. It generates an essentially quasistatic axial magnetic field which induces a circular electric field in the tissue. The receiving 3D contacting applicator contains a high-permittivity ceramic and is resonant. Its mode field provides the desired polarisation sensitivity and filters out the main electric field. The overall system sensitivity for detection of internal inhomogeneities is accomplished by optimised use of the orthogonality of the primary magnetic, induced electric, and diffracted electric fields. When developments are completed, the system will replace or complement existing commercial technologies at a low cost.

  • 21.
    Petrović, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik. Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Measurement System for Microwave Imaging Towards a Biomedical Application2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Microwave imaging techniques have shown excellent capabilities in various fields such as civil engineering, nondestructive testing, industrial applications, and have in recent decades experienced strong growth as a research topic in biomedical diagnostics. Many research groups throughout the world work on prototype systems for producing images of human tissues in different biomedical applications, particularly breast tumor detection. However, the research community faces many challenges and in order to be competitive to other imaging modalities one of the means is to put emphasis on experimental work. Consequently, the use of flexible and accurate measurement systems, together with the design and fabrication of suitable antennas, are essential to the development of efficient microwave imaging systems.

    The first part of this thesis focuses on measurement systems for microwave imaging in terms of antenna design and development, robot controlled synthetic array geometries, permittivity measurements, and calibration. The aim was to investigate the feasibility of a flexible system for measuring the fields around an inhomogeneous object and to create quantitative images. Hence, such an aim requires solving of a nonlinear inverse scattering problem, which in turn requires accurate measurements for producing good quality experimental data. The presented solution by design of a flexible measurement system is validated by examination of microwave imaging from experimental data with a breast phantom.

    The second part of the thesis deals with the research challenges of designing high performance antennas to be placed in direct contact with or in close proximity to the imaged object. The need for novel antenna applicators is envisaged in the framework of the Mamacell measurement system, where the antenna applicators have to be designed and constructed to effectively couple the energy into the imaging object. For this purpose the main constraints and design requirements are a narrow lobe of the antenna, very small near-field effects, and small size. Numerical simulations and modeling shows that the proposed ridged waveguide antenna is capable of fulfilling the design requirements and the performance goals, demonstrating the potential for the future microwave imaging system called Mamacell.

  • 22.
    Prytz, Erik
    et al.
    Linköpings Universitet.
    Kristoffersson, Annica
    Örebro Universitet.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Ahmed, Mobyen Uddin
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Lind, Leili
    Linköpings Universitet.
    E-care@home: Initial Usability Considerations2016Inngår i: Abstractproceedings from Medicinteknikdagarna 2016, Örebro, Sweden, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The E-care@home project aims to develop a smart sensor and communication infrastructure with semantic interoperability capable of monitoring patients in their home. The system will use a wide array of sensors, both medical and environmental, and an advanced computer reasoning layer capable of interpreting sensor data and deliver natural language summaries of the patient health status. One critical issue is that of the usability of such a system to the users, i.e. patients and care providers.

  • 23.
    Risman, Per Olov
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    MICROWAVE ANTENNA APPLICATOR2015Patent (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    A new and comparatively small type of open-ended microwave applicators has been disclosed. They are for example suitable for transmission into and reception from contacting objects such as protruding human bodyparts for inhomogeneity detection by tomographic methods. The applicators according to the invention are of the dielectric-filled open-ended ridged rectangular TE10 type, with an insert filling the ridge and having a higher permittivity than the surrounding space. The shape of the insert can be as a frustrum pyramid towards the opening. The overall design promotes narrow beamwidths and minimises nearfields and surface wave excitation.

  • 24.
    Risman, Per Olov
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Otterskog, Magnus
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. IS (Embedded Systems).
    Översikt av mikrovågsbaserad diagnostik för brösttumörer och stroke2017Inngår i: Medicinteknikdagarna 2017 MTD 2017, Västerås, Sweden, 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Forskningsområdet mikrovågsavbildning inom medicinen introducerades redan på 1980-talet av Larsen och Jacobi [1]. Objektet var en hundnjure nedsänkt i en mikrovågsabsorberande vätska (bolus) för att undvika störningar och direkt koppling mellan de två roterande antennmatriserna. Man fann att intressant mikrovågskontrastverkan kunde uppnås i biologiska objekt. Fördelar jämfört med mammografi är ex.vis att strålningen är helt ofarlig och att man kan »se» närmare revbenen. Nackdelen är att detaljbilden blir sämre om objektet är stort. Ett relativt enkelt sådant system har utvecklats på MDH [2]. System av denna typ innefattar krav på omfattande matematiska beräkningar för att få fram en bild. Idag anses den ledande utvecklingen ske av Meaney [3] som nu även tar fram ett system på Chalmers i Göteborg. System för stroke- och hjärnblödningsdetektion är under utveckling hos EMTensor i Österrike [4,5] och Medfield diagnostics i Göteborg [6]. Problemen med direkt vågutbredning med s.k. ytvågor längs skallytan blir stora eftersom man inte kan sänka ned skallen i vätska. Absorberande s.k. bolusar och även viss metallisk avskärmning (»huva») används av EM Tensor. En forskningsgrupp under Abbosh [7] har i laboratoriemiljö helt utan störningar lyckats uppnå vissa resultat utan bolusanvändning. Typiska antenner är modifierade kommunikationsantenner och man använder ett spektrum av frekvenser. Återigen blir systemen beräkningsintensiva. På MDH utvecklas f.n. två olika system. Det första har tredimensionella antenner och speciella åtgärder för eliminering av ytvågorna [8] samt kräver matematiska beräkningar som alla de föregående. Det andra bygger på en annan princip: polariserad direktdetektion av den. s.k. diffraktionen från exv. hjärnblödningsområdet och användning av vad som inte är antenner i vanlig mening [9]. Endast mycket enkel bildbehandling krävs, inte heller statistisk träning krävs för framtagning av slutdata så som tillämpas i exv. oljeindustrin för bestämning av olja/vatten/gas med mikrovågsteknik. Sammanfattningsvis karaktäriseras området av ett flertal aktiviteter, varav några pågått i många år. Orsaker till tidsutdräkterna är dels givetvis de allmänna svårigheterna med mikrovågsavbildning, men en ytterligare orsak är att mikrovågsvetenskapen och tekniken i sig är tvärvetenskaplig. En konsekvens av detta är att man inte tillräckligt tidigt ägnat sig åt de speciella ytvågs- och diffraktionsfenomen som kan förbättra mätresultaten.

  • 25.
    Risman, Per Olov
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Arch-Trapped Propagation in Enclosed and Free Space Biological Objects2018Inngår i: 2018 IEEE CAMA Conference on Antenna Measurement and Applications CAMA 2018, 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The tendency of arch-trapped microwave propagation at curved surfaces is a kind of diffraction which needs more attention in the development of measurement systems, from the oil industry to the investigations using antenna applicator systems for biological objects. We develop equations for propagation in very lossy substances in metal pipes. Similar such propagation occurs at the periphery of rounded objects in air, where also surface wave effects occur and can cause measurement problems. We show a modified contacting antenna applicator minimizing arch-trapped as well as surface waves.

  • 26.
    Tomasic, Ivan
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Fotouhi, Hossein
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    IoT enabled monitoring of patients’ environmental parameters supported by OpenWSN, OpenMote, and relational databases2018Inngår i: Medicinteknikdagarna 2018 MTD 2018, 2018Konferansepaper (Fagfellevurdert)
  • 27.
    Tomasic, Ivan
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Fotouhi, Hossein
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Data flow and collection for remote patients monitoring: From wireless sensors through a relational database to a web interface in real time2017Inngår i: IFMBE Proceedings, Springer Verlag , 2017, s. 89-92Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A reliable, secure, and real-time data collection from sensor devices to the end-user is an open research problem. Many research works have been focusing on the wireless communication level to obtain quality of service. This paper widens the problem, and provides a comprehensive system design, where it covers all the elements in a remote health monitoring application. The system collects measurements in a relational database, either through a C#.NET or a LabVIEW program. The end-user is able to observe either real-time data (i.e. with insignificant delay) or processed historical data on any web browser. We have shown that the inclusion of the relational database may impose a need for the data to be buffered before inserting into the database within a single transaction, but the buffering does not entail delays bigger than 50 ms. 

  • 28.
    Tomasic, Ivan
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Rashkovska, A.
    Jolef Stefan Inst, Dept Inst Commun Syst, Ljubljana, Slovenia..
    Comparison of publicly available beat detection algorithms performanances on the ECGs obtained by a patch ECG device2019Inngår i: 2019 42ND INTERNATIONAL CONVENTION ON INFORMATION AND COMMUNICATION TECHNOLOGY, ELECTRONICS AND MICROELECTRONICS (MIPRO) / [ed] Koricic, M Butkovic, Z Skala, K Car, Z CicinSain, M Babic, S Sruk, V Skvorc, D Ribaric, S Gros, S Vrdoljak, B Mauher, M Tijan, E Pale, P Huljenic, D Grbac, TG Janjic, M, IEEE , 2019, s. 275-278Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Eight ECG beat detection algorithms, from the PhysioNet's WFDR and Cardiovascular Signal toolboxes, were tested on twenty measurements, obtained by the Savvy patch ECG device, for their accuracy in beat detection. On each subject, one measurement is obtained while sitting and one while running. Each measurement lasted from thirty seconds to one minute. The measurements obtained while running were more challenging for all the algorithms, as most of them almost perfectly detected all the beats on the measurements obtained in sitting position. However, when applied on the measurements obtained while running, all the algorithms have performed with decreased accuracy. Considering overall percentage of the faulty detected peaks, the four best algorithms were jqrs, from the Cardiovascular Signal Toolbox, and ecgpuwave, gqrs, and wqrs, from the WEDB Toolbox, with percentages of faulty detected beats 1.7, 2.3, 2.9, and 3, respectively.

  • 29.
    Tomasic, Ivan
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Petrovic, Nikola
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Rashkovska, A.
    Jožef Stefan Institute, Department of Communication Systems, Ljubljana, Slovenia.
    Comparison of publicly available beat detection algorithms performances on the ECGs obtained by a patch ECG device2019Inngår i: 2019 42nd International Convention on Information and Communication Technology, Electronics and Microelectronics, MIPRO 2019 - Proceedings, Institute of Electrical and Electronics Engineers Inc. , 2019, s. 275-278Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Eight ECG beat detection algorithms, from the PhysioNet's WFDB and Cardiovascular Signal toolboxes, were tested on twenty measurements, obtained by the Savvy patch ECG device, for their accuracy in beat detection. On each subject, one measurement is obtained while sitting and one while running. Each measurement lasted from thirty seconds to one minute. The measurements obtained while running were more challenging for all the algorithms, as most of them almost perfectly detected all the beats on the measurements obtained in sitting position. However, when applied on the measurements obtained while running, all the algorithms have performed with decreased accuracy. Considering overall percentage of the faulty detected peaks, the four best algorithms were jqrs, from the Cardiovascular Signal Toolbox, and ecgpuwave, gqrs, and wqrs, from the WFDB Toolbox, with percentages of faulty detected beats 1.7, 2.3, 2.9, and 3, respectively. 

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