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  • 101.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Electrical Bioimpedance Cerebral Monitoring: Fundamental Steps towards Clinical Application2007Doctoral thesis, comprehensive summary (Other academic)
  • 102.
    Seoane, Fernando
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Univ Boras, Fac Care Sci Work Life & Social Welfare, Sweden.
    Abtahi, Shirin
    Abtahi, Farhad
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Karolinska Inst, Dept Clin Sci Intervent & Technol, Sweden.
    Ellegård, Lars
    Johannsson, Gudmundur
    Bosaeus, Ingvar
    Ward, Leigh C
    Mean Expected Error in Prediction of Total Body Water: A True Accuracy Comparison between Bioimpedance Spectroscopy and Single Frequency Regression Equations2015In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, article id 656323Article in journal (Refereed)
    Abstract [en]

    For several decades electrical bioimpedance (EBI) has been used to assess body fluid distribution and body composition. Despite the development of several different approaches for assessing total body water (TBW), it remains uncertain whether bioimpedance spectroscopic (BIS) approaches are more accurate than single frequency regression equations. The main objective of this study was to answer this question by calculating the expected accuracy of a single measurement for different EBI methods. The results of this study showed that all methods produced similarly high correlation and concordance coefficients, indicating good accuracy as a method. Even the limits of agreement produced from the Bland-Altman analysis indicated that the performance of single frequency, Sun’s prediction equations, at population level was close to the performance of both BIS methods; however, when comparing the Mean Absolute Percentage Error value between the single frequency prediction equations and the BIS methods, a significant difference was obtained, indicating slightly better accuracy for the BIS methods. Despite the higher accuracy of BIS methods over 50 kHz prediction equations at both population and individual level, the magnitude of the improvement was small. Such slight improvement in accuracy of BIS methods is suggested insufficient to warrant their clinical use where the most accurate predictions of TBW are required, for example, when assessing over-fluidic status on dialysis. To reach expected errors below 4-5%, novel and individualized approaches must be developed to improve the accuracy of bioimpedance-based methods for the advent of innovative personalized health monitoring applications.

  • 103.
    Seoane, Fernando
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Bragós, Ramon
    Technical University of Catalonia.
    Lindecrantz, Kaj
    Current Source for Wideband Electrical Bioimpedance Spectroscopy Based on a Single Operational Amplifier2006In: WORLD CONGRESS ON MEDICAL PHYSICS AND BIOMEDICAL ENGINEERING 2006, VOL 14, PTS 1-6 / [ed] Kim, SI; Suh, TS, 2006, p. 707-710Conference paper (Refereed)
    Abstract [en]

    Traditionally, measurements of electrical bioimpedance for medical diagnostic purposes have used only low frequencies, usually below 100 kHz. The analysis focused only on the resistive part of the impedance; very often at low frequencies the reactive part of the impedance is negligible. Recent studies of the electrical bioimpedance spectrum, both real and imaginary parts, have indicated new potential applications e.g. detection of meningitis, skin cancer assessment and brain cellular edema detection. An important functional unit in a wideband impedance spectrometer is the current source used to inject the current into the tissue under study. A current source must provide an output current virtually constant over the frequency range of interest and independent of the load at the output. Several designs have been proposed over the years but the performance of them all degraded markedly near bellow 1 MHz e.g. Ackmann in 1993, Bragos et al in 1994 and Bertemes-Filho et al in 2000. The development of electronic technology has made available devices that allow us to obtain a current source with large output impedance, larger than 100 k Omega, above I MHz and based in a simple single Op-Amp circuit topology. Simulation results and experimental measurements are compared and the most important parameters of the VCCS are analytically studied and experimentally tested, including the dependency to changes in the circuit elements and the incidence of the Op-Amp parameters on the current source features.

  • 104.
    Seoane, Fernando
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Ferreira, Javier
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Buendia, Ruben
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Adaptive frequency distribution for Electrical Bioimpedance Spectroscopy measurements2012In: Engineering in Medicine and Biology Society (EMBC), 2012 Annual International Conference of the IEEE, IEEE , 2012, p. 562-565Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel frequency distribution scheme intended to provide more accurate estimations of Cole parameters. Nowadays a logarithmic frequency distribution is mostly used in Electrical Bioimpedance Spectroscopy (EBIS) applications. However it is not optimized following any criterion. Our hypothesis is that an EBIS signal contains more information where the variation of the measurement regarding the frequency is larger; and that there ought to be more measuring frequencies where there is more information. Results show that for EBIS data with characteristic frequencies up to 200 kHz the error obtained with both frequency distribution schemes is similar. However, for EBIS data with higher values of characteristic frequency the error produced when estimating the values from EBIS measurements using an adaptive frequency distribution is smaller. Thus it may useful for EBIS applications with high values of characteristic frequency, e.g. cerebral bioimpedance.

  • 105.
    Seoane, Fernando
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Lindecrantz, Kaj
    Influence of the Skull and the Scalp on the Electrical Impedance of the Head and the Implications on Detection of Brain Cellular Edema2005In: IFMBE proceedings of the 12th International Conference on Biomedical Engineering, Singapore: Springer , 2005Conference paper (Refereed)
  • 106. Shimada, A.
    et al.
    Kasai, N.
    Furukawa, Y.
    Nyberg, Tobias
    KTH, School of Technology and Health (STH), Neuronic Engineering (Closed 20130701).
    Torimitsu, K.
    Neural signal transmission measurements with a conductive polymer microelectrode array2009In: IEEJ Transactions on Electronics, Information and Systems, ISSN 0385-4221, Vol. 129, no 2, p. 267-271+10Article in journal (Refereed)
    Abstract [en]

    The neural activity of dissociated cultures of mouse cerebral cortical neurons was measured with a conductive polymer microelectrode array. Each electrode was electrochemically polymerized from (3,4-ethylenedioxythiophene)- poly(styrenesulfonate) and ethylenedioxythiophene on indium tin oxide electrodes. The spike activity of the cortical neurons was measured with the conducting polymer MEA and spike train cross-correlograms were calculated to predict the type of synaptic connection. Both excitatory and inhibitory synaptic connections were identified after 6-8 days in vitro. These results show that it is possible to determine the interaction between excitatory and inhibitory neurons in relation to information processing with this new polymer electrode.

  • 107. Shimada, Akiyoshi
    et al.
    Kasai, Nahoko
    Furukawa, Yuriko
    Nyberg, Tobias
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Torimitsu, Keiichi
    Neural Signal Transmission Measurements with a Conductive Polymer Microelectrode Array2011In: Electrical engineering in Japan (Print), ISSN 0424-7760, E-ISSN 1520-6416, Vol. 177, no 1, p. 37-42Article in journal (Refereed)
    Abstract [en]

    The neural activity of dissociated cultures of mouse cortical neurons was measured with a conductive polymer microelectrode array. Each electrode was electrochemically polymerized from (3,4-ethylenedioxythiophene)-poly(styrenesulfonate) and ethylenedioxythiophene on indium tin oxide electrodes. The spike activity of the cortical neurons was measured with the conducting polymer MEA and spike train cross-correlograms were calculated to predict the type of synaptic connection. Both excitatory and inhibitory synaptic connections were identified after 6 to 8 days in vitro. These results show that it is possible to determine the interaction between excitatory and inhibitory neurons in relation to information processing with this new polymer electrode.

  • 108.
    Shreenath, Vinutha Magal
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Health Care Logistics.
    Kornevs, Maksims
    KTH, School of Technology and Health (STH), Health Systems Engineering, Health Care Logistics.
    Raghothama, Jayanth
    Meijer, Sebastiaan
    KTH, School of Technology and Health (STH), Health Systems Engineering, Health Care Logistics.
    A Feasibility Study for Gamification in Transport Maintenance: Requirements to implement gamification in heterogeneous organizations2015In: Games and Virtual Worlds for Serious Applications (VS-Games), 2015 7th International Conference on, IEEE conference proceedings, 2015, p. 1-7Conference paper (Refereed)
    Abstract [en]

    Gamification has been successfully applied in many domains, but mostly for simple, isolated and operational tasks. The hope for gamification as a method to radically change and improve behavior, to provide incentives for sustained engagement has proven to be more difficult to get right. Applying gamification in large networked organizations with heterogeneous tasks remains a challenge. Applying gamification in such enterprise environments posits different requirements, and a match between these requirements and the institution needs to be investigated before venturing into the design and implementation of gamification. The current paper contributes a study where the authors investigate the feasibility of implementing gamification in Trafikverket, the Swedish transport administration. Through an investigation of the institutional arrangements around data collection, procurement processes and links to institutional structures, the study finds areas within Trafikverket where gamification could be successfully applied, and suggests gaps and methods to apply gamification in other areas.

  • 109.
    Strand, Mathias
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Standardisering av processer och aktiviteter inom kontrollanläggningar och elmontage2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this thesis, a study has been carried out for the consulting company ÅF, and their work method within documentation and control facilities to investigate whether there were any potential for efficiency improvements. The investigation has largely involved interviews with operating consultants within the control facility on substations. The consultants worked as electrical designers and produced drawings mainly for control equipment. The results of the interviews were analyzed to draw conclusions about the efficiency potentials within the business. Different offices in the business were examined and the work approach varied between the offices. One difference was the CAD-software used and a suggestion was to use the same program. Efficiency improvement potentials were also by re-using electrical schematics to some extent from previous projects and another suggestion was to establish databases where electrical schematics can be gathered and shared between the different offices.

  • 110.
    Sturm, Dennis
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Wireless Multi-Sensor Feedback Systems for SportsPerformance Monitoring: Design and Development2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Wireless applications have become a common part of daily life. Whether it is mobile phones, the Wi-Fi router at home, the keycard which has replaced the car key, a radio frequency identification access system to a building or a Bluetooth headset for your computer or phone, the means of modern wireless data exchange is an omnipresent technology. In sports, the market is in its infancy for wireless, technical applications or gadgets. Only heart rate monitors and GPS watches are currently used by recreational athletes. Even though most of the larger sports equipment companies regularly launch new products related to sports performance monitoring and mobile phone technology, product innovation leaps are rare.In this work the design of a wireless sports performance measurement platform is presented. Using the example of kayaking, this platform is configured as a paddle performance measuring system, the Kayak XL System, which can monitor propulsive paddle force, paddle kinematics and boat velocity, interalia. A common mobile phone platform has been chosen as the user interface for this system. The design approach focussing on user requests, demands and expectations in combination with the process of iterative technical development are unveiled in this thesis. An evaluation of the system is presented and the work is finalised with an overview of further systems which have been designed based on the developed measurement platform. The Kayak XL System is a flexible system designed to be mounted onto any standard kayak paddle and installed in any competition kayak. Versatility, unobtrusiveness and usability were major design concerns. The developed system consists of four modules plus a software which has been designed for Android mobile phones. The phone communicates with each of the four modules trough Bluetooth radio. These four modules are also referred to as nodes and have specific measurement purposes. Two nodes have been designed to measure paddle force and kinematics, one node has the purpose to measure foot stretcher force and boat motion data, and the fourth node enables a more convenient method of calibrating paddle force measurement. The fourth node is therefore only needed prior to performance data acquisition. Results show that paddle and foot stretcher force can be measured with a resolution below 1N after calibration. Installing the paddle nodes on a previously configured paddle without repeated calibration is facilitated with the compromise of a doubled error margin. The default sampling frequency is set to 100 Hz and can, like all system parameters, be configured on the mobile phone. Real-time computation of complex performance parameters is only limited by the phone CPU. The system adds twice 109 g to the paddle and approximately 850 g to the kayak, excluding the mass of the mobile phone

  • 111.
    Sturm, Dennis
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Parida, Vinit
    Luleå University of Technology.
    User-centred Research and Technology Development: A Study of a Swedish University Project2012In: International Journal of Business and Management Tomorrow, ISSN 2249-9962, Vol. 2, no 1, p. 1-11Article in journal (Refereed)
    Abstract [en]

    University research is required to be more need-driven and user-centred in order to address research problemsand market needs. However, there is a lack of understanding regarding the research approach, which can be used effectively to address the dual goals. In this study, we provide a detailed explanation regarding user-centred research approach used in a Swedish university research project. Our results suggest that integration of potential customers and lead users into the research and development stages represents a critical step for ensuring marketability of the innovative product. In addition, we highlight four specific stages related to the proposed research approach and list specific activities related to these research and development stages.

  • 112.
    Sturm, Dennis
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Yousaf, Khurram
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Halvorsen, Kjartan
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701). Uppsala University, Uppsala, Sweden .
    Wireless kayak on-water ergometry - Part 1: Paddle blade force2013In: Sports Technology, ISSN 1934-6182, E-ISSN 1934-6190, Vol. 6, no 1, p. 29-42Article in journal (Refereed)
    Abstract [en]

    The aim of this work was to present a new wireless paddle force measurement system and to evaluate this measurement system. The system is redeveloped from a previous design and includes inertial motion sensors, which allows for the movement and inertia of the paddle to be taken into account. The system consists of two sensor nodes, designed for quick attachment to virtually any kayak paddle and an Android phone or tablet. Each sensor node measures the bending of the shaft in one plane. We derive the expressions necessary for computing the force on the paddle blade in two directions, ignoring the force in the direction of the shaft. Two different schemes for calibrating the system are presented. The accuracy and reliability of the system is evaluated in a laboratory setting using a material testing machine. An average error of 0.4% can be achieved for force measurements following directly after calibration. When the sensors are removed and reattached between calibration and measurements, average error between loading and measured force increased to 2.0% (linear model) and 1.8% (quadratic model). The limits of agreement depend on the position of the sensor nodes along the shaft and the feather angle if transverse sensitivity of the sensors is used to determine two-dimensional force on the paddle blade. On-water stroke force is presented, averaged over 10 strokes for each side with force levels >200 N to show the applicability of the study. The accuracy of the measurement is affected by the calibration method, placement of the paddle nodes and the shaft's properties.

  • 113.
    Sturm, Dennis
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Yousaf, Khurram
    KTH, School of Technology and Health (STH), Medical Engineering.
    Eriksson, Martin
    KTH, School of Technology and Health (STH), Medical Engineering.
    A Kayak Training System for Force Measurement on-water2010Conference paper (Refereed)
    Abstract [en]

    Kayaking is a very competitive sport and represented in the Olympic context with two disciplines: slalom and flatwater. The main forces that propel the boat are paddle and foot stretcher force (Mann & Kearney, 1980). Anecdotal evidence collected from coaches involved in the research suggests varying theories on the best profile and synchronisation of paddle and foot stretcher force. It should be extremely helpful for athletes, coaches and researchers to measure these forces in real-time on-water with an unobtrusive, wireless sensor system such as is presented here. Thereby athletes are provided the possibility to perform their training with knowledge of performance (KP), which leads to superior training effects compared to knowledge of results (KR) only. The authors have not been able to identify any previous studies examining paddle and foot stretcher forces simultaneously although previous work has suggested doing so (Michael et al. 2009, Petrone et al., 1998).

  • 114.
    Sturm, Dennis
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Yousaf, Khurram
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Eriksson, Martin
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    A wireless, unobtrusive Kayak Sensor Network enabling Feedback Solutions2010In: 2010 International Conference on Body Sensor Networks, BSN 2010, 2010, p. 159-163Conference paper (Refereed)
    Abstract [en]

    Canoeing is a very competitive sport involving a non-trivial pattern of motion. A group of athletes and coaches approached the authors for aid in quantifying what until today only is qualitative, personal and thereby subjective data. The objective of this work is to present a measurement tool that records paddle and foot stretcher force in a flatwater kayak training situation, i.e. when training on the water. The system facilitatesa wireless (Bluetooth) star network link with three sensor nodes and one central unit. Validation data was obtained from a kayak ergometer that is equipped with analysis software. The stroke power obtained from this ergometer system is compared to the force data measured by the presented wireless sensor nodes. We have not been able to find any similar systems that would provide better data for performance analysis.

  • 115.
    Sturm, Dennis
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Yousaf, Khurram
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Eriksson, Martin
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Tornberg, Åsa B.
    Halvorsen, Kjartan
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Validation of a novel wireless Force Measurement System for Kayak Paddle ShaftsManuscript (preprint) (Other academic)
  • 116.
    Sturm, Dennis
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Yousaf, Khurram
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Halvorsen, Kjartan
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Eriksson, Martin
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Håkansson, Paul
    Lund University.
    Segerström, Åsa
    Lund University.
    Measuring Kayak Paddle Performance with Wireless Strain Sensors on the Shaft: A Validation Study2011Conference paper (Refereed)
  • 117.
    Svensson, Johan
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Mätning av skärgradshöjd på stål2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today, a steel roll is cut within the steel industry in a cutting factory, the steel rollsare divided to smaller part bands with poor control of the burr height quality. Samplesis taken manually, the amount of samples is too low to know the quality of thesteel roll, the steel rolls can be divided up to 150 times and the length will be 30 kilometers. A whole resend for one steel roll costs up against a million SEK and has anegative climatic impact. One software prototype for detection of burr heights witha reference line was programmed. The prototype contained one light sensor, two motors,a PC and one prototype construction. Each task in the software was allocatedan own thread. Operating systems, threads and algorithms was performance testedfor measurement of execution times and period times. The result showed that a burrheight detector where possible to implement. The algorithm could detect burrheights that were too large related to its reference line.

  • 118.
    Svensson Marcial, Alexander
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Gatu, Andreas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Justerbar modell av transmissionsledning för elkraftsöverföring2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete har utförts på uppdrag av Terco. Tercos PST 2220 Transmission Line and Distribution Module fungerar som en fysisk modell av ett verkligt transmissions- eller distributionsnät där fem olika typer av nät med avseende på längd, spänningsnivå och skenbar effekt är möjliga. Idag finns ett behov av en modell där användaren kan ställa in dessa parametrar så att modellen mer precist kan spegla vilka egenskaper det specifika nätet har. Här undersöks hur längden och dess inverkan på en ledning kan varieras i en modell. En presentation av hur transmissions- och distributionsnät fungerar och beskrivs teoretiskt lägger grunden till den modell och de två approximationer som kan beskriva ett helt näts egenskaper. Då R, L och C komponenterna behöver kunna varieras för att fysiskt kunna realisera denna teoretiska modell undersöks vilka metoder som detta kan genomföras på. För detta undersöks två tillvägagångssätt, kaskadkopplad pi-modell och variabel aktiv-passiv reaktans. Flera aspekter som utrymme, kostnad och variabilitet gör att variabel aktiv-passiv reaktans är att föredra. Dess funktion som en varierbar spänningskälla, uppbyggd av switchar styrda med reglerteknik och pulsbreddsmodulering gör att komponenterna R, L och C och dess egenskaper och inverkan på en transmissionslinje kan åstadkommas. Resultatet är att de nödvändiga R,L,C komponenterna går att variera i storlek för att kunna ingå i en varierbar transmissionsledningsmodell. Resultatet och målen säkerställs med simuleringar där variabel aktivpassiv reaktans visas kunna vidareutvecklas och praktiskt testas för att modellera transmissions- och distributionsnät med olika längd.

  • 119.
    Söderholm, Daniel
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Fröberg, Markus
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Energismart bevattningssystem2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Energy smart solutions are up to date and all opportunities to save energy are considered essential for protection of nature. Energy can be saved on irrigation systems by not watering if rain is approaching. By monitoring weather forecasts, the rainfall can be analyzed and irrigation adjusted accordingly.

     

    The projects goal is to create an energy smart irrigation system designed to prevent unwanted watering. By using soil moisture sensors and analyze weather data, the irrigation amount will be determined depending on the soil moisture and upcoming rainfall. Through a web page, there are configuration options and information about the system.

     

    This report explains the sensor nodes and its various functionalities in the system. The associated soil moisture sensors characteristics and its calibration are described. The water pump and its associated controlling are also treated. The system’s server and database are described as well as the link between them. There is also a flowchart of the server’s functionality. It explains how the weather data is collected and analyzed to access impending rainfall.

     

    The system's web page is shown and described with its configuration options and its status information. It also explains how the sensor motes are added, removed and edited on the website and in the system.

     

    The results summarize the work with how the different parts are linked together to form the energy smart irrigation system. An installation guide and a user manual have also been created.

  • 120.
    Vega-Barbas, Mario
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Pau, Ivan
    Universidad Politecnica de Madrid.
    Martín-Ruiz, Maria Luisa
    Universidad Politecnica de Madrid.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Adaptive Software Architecture Based on Confident HCI for the Deployment of Sensitive Services in Smart Homes2015In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 15, no 4, p. 7294-7322Article in journal (Refereed)
    Abstract [en]

    Smart spaces foster the development of natural and appropriate forms of human-computer interaction by taking advantage of home customization. The interaction potential of the Smart Home, which is a special type of smart space, is of particular interest in fields in which the acceptance of new technologies is limited and restrictive. The integration of smart home design patterns with sensitive solutions can increase user acceptance. In this paper, we present the main challenges that have been identified in the literature for the successful deployment of sensitive services (e.g., telemedicine and assistive services) in smart spaces and a software architecture that models the functionalities of a Smart Home platform that are required to maintain and support such sensitive services. This architecture emphasizes user interaction as a key concept to facilitate the acceptance of sensitive services by end-users and utilizes activity theory to support its innovative design. The application of activity theory to the architecture eases the handling of novel concepts, such as understanding of the system by patients at home or the affordability of assistive services. Finally, we provide a proof-of-concept implementation of the architecture and compare the results with other architectures from the literature.

  • 121.
    Vega-Barbas, Mario
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Pau, Ivan
    Univerisdad Politecnica de Madrid.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Confidence: dependencies and their critical role in fostering user acceptance in pervasive applications2014Conference paper (Refereed)
    Abstract [en]

    Pervasive computing offers new scenarios where users are surrounded by invisible and proactive technology making smart spaces. Although the utility and power of solutions developed using this computer paradigm are proved, there are unresolved problems that hinder their acceptance and inclusion in our private life. Users have problems understanding the operations of a pervasive computing solution, and therefore they should trust that the solution works properly and according to their expectations. Nevertheless, the concept of trust is already framed in a specific use within the ecosystem of applications that can populate a smart space. To take this concept of trust to the whole space, we propose to study and define the concept of confidence. In contrast to the concept of trust, confidence has deeper psychological implications.

  • 122.
    Vega-Barbas, Mario
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Universidad Politécnica de Madrid, Spain.
    Pau, Ivan
    Universidad Politecnica de Madrid.
    Valero, Miguel Angel
    Universidad Politecnica de Madrid.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. University of Borås, Sweden.
    Adaptive Software Architecture for Confident Homecare in the Digital Home2014Conference paper (Refereed)
    Abstract [en]

    Smart spaces foster the development of more natural and suitable forms of human-computer interaction taking advantage of customization possibilities offered by the home. The interaction chances of the Digital Home, as a special type of smart space, have a special interest in fields where the acceptance of new technologies is low and restrictive. Homecare is a discipline where this acceptance is more problematic. The integration of digital home design patterns in homecare solutions should enhance the final acceptance of users. In this position paper, we present the main challenges identified from the literature for the successful implementation of homecare solutions in smart spaces and the design of a software architecture that models entities and functionalities involved in solving these challenges.

  • 123.
    Villabona, Antonio
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Dietrichson, Fredrik
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Effektivisera generering av parameterfiler för betalterminaler2014Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    This thesis describes the process of analyzing and evaluating the structure of data storage and improving the performance for generating parameter files destined for card terminals. The work was done in house at Esplanad AB, a company dealing with security solutions and distribution of settings for payment stations.

    The first task was to evaluate the possibilities for improving the database storing the settings for each card reader. The second task was to improve the structure of the code and also improve the file generating systems performance.

    The thesis describes testing performance, both for Esplanad’s old system for generating parameter files, and the new one constructed. The solution presented includes improved performance of the file generating process and a new structure for the database that increases scalability.

    Tests show that the new system is capable of generating parameter files with TLV-format, about 16 times faster. The proposed solution implements parallel processes and database replication.

  • 124.
    Wazir, Omerjan
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Frantsalis, Ioannis
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Prestandautvärdering av Bluetooth och Wi-Fi för en smart hubb2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis has been carried out on behalf of the consulting company Seavus to re-duce cable usage in their office. Smart hubs (i.e. a central control unit) are made tomake usage of devices more effective.One problem is to decide between Bluetooth and Wi-Fi for communication betweenthe user and the smart hub. The choice may depend upon several factors such asbandwidth (throughput), jitter (variation in delay) and packet loss, which are im-portant parameters for assessing the quality of the communication channel.The HW-platform Raspberry Pi and compatible software was used as a measure-ment tool to test Bluetooth and Wi-Fi in different environments.The result showed that Wi-Fi is best suited for communication systems that requirehigh bandwidth and low jitter, and where high amount of packet loss is tolerable.Bluetooth is best suited for communication systems where low bandwidth and highjitter is tolerable, and minimal packet losses preferred.

  • 125.
    Wernersson, Johan
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Automatiserad elektrisk testning av styrenheter: Styrenheter med verkliga laster i befintliga testriggar2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis work intends to study the possibilities to automate electrical testing of electronic control units in an existing test environment. The work was executed on behalf of Scania CV AB for the department Electronic Hardware, who run tests in development and verification of requirements for electronic control units. By using an automated testing system, the testing process could be made more effective and raise the quality. The testing work is done on test rigs which are equipped with full-scale hardware from real trucks to emulate the working environment the electronic control unit operates into. Development models were used to be able to create a testing system which could meet the requirements that were defined during the requirement engineering process. Evaluation matrices were used to choose the soft- and hardware that could be considered the most appropriate for the automated testing system according to the requirements. The result shown that the testing system should consist of a testing software that runs on an ordinary computer and an embedded system equipped with electronic components to enable the testing system for electrical tests. To demonstrate the possibilities of the whole testing system a prototype was manufactured which was designed to execute a test case that could greatly benefit from the advantages that comes with automation. It was a test case set out to measure voltage levels when switching in a digital input. The prototype was based on a microcontroller card from Arduino and was joined by a printed circuit board to be able to run electrical tests with the higher voltage levels that were demanded by electronic control units. To design test cases and manage the test process, LabVIEW was chosen, a software in which tests are designed in a graphical programming language. Test results for the prototype test system showed that verification of the requirements for voltage levels when switching was radically simplified by an automated procedure, as the test time could be drastically reduced, particularly in a repetitive procedure.

  • 126.
    Westerberg, Rickard
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Lösningsalternativ för strömförsörjningsproblem på Nockebybanan och Tvärbanan2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Several problems regarding power supply of Nockebybanan and Tvärbanan tram lines have been detected. The goal of this work has been to investigate and solve some of these problems. One of the problems was that so called relay protections were breaking the current too often, even when there was no fault. The protections also often break the power supply because of current transients, which can arise when a pantograph passes a section delimiter or in the winter when there is hoarfrost on the catenary.

    The result of the investigation and analysis shows different solutions, of which one appropriate procedure for reducing the number of breaks in the rectifier stations, is to limit the current in the trams so that they are not able to use as much current. This procedure was not possible to develop for the tram manufacturer alredy to the autumn of 2017, only a power limitation was the option for the short time perspective. An investigation of the settings of the relay protections was proposed as a procedure to reduce the number of breaks and was done by Siemens. The aim was to investigate if the relay protection could be readjusted so that the number of breaks could be reduced. The investigation showed that the so called derivative protection could be readjusted a bit. In this thesis work, it was also proposed that the lapse when a tram passes a section delimiter should be investigated, and was done so by the tram manufacturer. Their result was supposed to be finished after the completion of this thesis work. Options for operating trams when there is hoarfrost on the catenary is investigated and a relatively simple solution is to let a roller apply glycerol on the overhead line, preventing hoarfrost.

  • 127.
    Wåhslén, Jonas
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Multi-Sensor Data Synchronization using Mobile Phones2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Body sensor networking is a rapidly growing technology. Today wearable sensors are used to measure and monitor e.g. pulse, temperature, skin conductance, heart activity, and movement (through GPS or inertial measurement units). Mobile phones can act as coordinating nodes in wireless personal area networks used in home automation, healthcare, sport and wellness e.g. to measure pulse and distance. Integration of data from multiple sources sensors (data fusion) means that data from each sensor node needs to be associated with data from other sensor nodes sampled at approximately the same time. Accurate methods for time synchronization are therefore a necessary prerequisite for reliable data fusion.

    This thesis studies time synchronization problems in Bluetooth piconets between multiple wireless sensor nodes connected to a mobile phone that acts as coordinating node. Three different algorithms to enable correct data fusion have been developed, implemented and evaluated. The first is a single clock solution that synchronizes multiple wireless sensor nodes based solely on the mobile phone’s clock. The other two algorithms synchronize the clocks in sensor nodes to the clock in the coordinating node. 

  • 128.
    Wåhslén, Jonas
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Real-time Performance Management of Assisted Living Services for Bluetooth Low Energy Sensor Communication2017In: Integrated Network and Service Management (IM), 2017 IFIP/IEEE Symposium on, IEEE conference proceedings, 2017Conference paper (Refereed)
    Abstract [en]

    PerfMon is a prototype implementation of a realtime performance management method for sensor data communication in assisted living applications. It is implemented in accordance with the specification for GATT services in Bluetooth low energy (BLE). PerfMon provides a tool for real-time performance monitoring and control for caregivers and service providers. Test results from monitoring and control of packet loss ratio related to alarm thresholds are presented. PerfMon is adapted to cloud-based web services using RESTful APIs and established object models. Performance management is a necessary component in an overall management system of IoT devices for healthcare and assisted living applications.

  • 129.
    Wåhslén, Jonas
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Smartphone-Centric Wi-Fi Device-to-Device Sensor Communication for User Mobility in AAL Services2016In: Personal, Indoor, and Mobile Radio Communications (PIMRC), 2016 IEEE 27th Annual International Symposium on, IEEE conference proceedings, 2016, p. 80-85Conference paper (Refereed)
    Abstract [en]

    This paper evaluates a use-case for smartphone-centric Wi-Fi device-to-device sensor communication that enables user mobility in ambient assisted living (AAL) services. A real-time performance measurement method has been developed and implemented to evaluate the smartphone’s ability to act as a hub and gateway for Wi-Fi connected sensor nodes. The results show that Wi-Fi Direct and Wi-Fi Hotspot are feasible solutions for smartphone-centric device-to-device communication that enables user mobility. In addition, a cloud-based web application for monitoring and displaying sensor data has been implemented.

  • 130.
    Wåhslén, Jonas
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Eriksson, Martin
    KTH, School of Technology and Health (STH).
    A novel approach to multi-sensor data synchronization using mobile phones2011In: Proceedings of the 5th International ICST Conference on Body Area Networks: BodyNets 2010, 2011, p. 171-174Conference paper (Refereed)
    Abstract [en]

    This paper presents a new algorithm for synchronization of data from multiple sensors arriving to a mobile phone's Bluetooth interface with possibly unknown and different sampling frequencies. A system that provides feedback signals to an athlete is one example where it is crucial to synchronize data from several wireless sensors; especially sensor nodes use different and unknown sampling rates.

  • 131.
    Wåhslén, Jonas
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Orhan, Ibrahim
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Eriksson, Martin
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    A novel approach to multi-sensor data synchronisation using mobile phones2013In: International Journal of Autonomous and Adaptive Communications Systems, ISSN 1754-8632, E-ISSN 1754-8640, Vol. 6, no 3, p. 289-303Article in journal (Refereed)
    Abstract [en]

    This paper presents a new algorithm for application layer synchronisation of data from multiple sensors arriving to a mobile phone's Bluetooth interface. A system that provides feedback signals to an athlete is one example where it is crucial to synchronise data from several wireless sensors. This paper also discusses synchronisation problems caused by unpredictable Bluetooth transmission performance. 

  • 132.
    Wåhslén, Jonas
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Orhan, Ibrahim
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Sturm, Dennis
    KTH, School of Technology and Health (STH), Centres, Centre for Technology in Medicine and Health, CTMH.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Performance evaluation of time synchronization and clock drift compensation in wireless personal area networks2012In: BodyNets '12 Proceedings of the 7th International Conference on Body Area Networks, ICST , 2012, p. 153-158Conference paper (Refereed)
    Abstract [en]

    Efficient algorithms for time synchronization, including compensation for clock drift, are essential in order to obtain reliable fusion of data samples from multiple wireless sensor nodes. This paper evaluates the performance of algorithms based on three different approaches; one that synchronizes the local clocks on the sensor nodes, and a second that uses a single clock on the receiving node (e.g. a mobile phone), and a third that uses broadcast messages. The performances of the synchronization algorithms are evaluated in wireless personal area networks, especially Bluetooth piconets and ZigBee/IEEE 802.15.4 networks. A new approach for compensation of clock drift and a realtime implementation of single node synchronization from the mobile phone are presented and tested. Finally, applications of data fusion and time synchronization are shown in two different use cases; a kayaking sports case, and monitoring of heart and respiration of prematurely born infants. 

  • 133.
    Wåhslén, Jonas
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik (Closed 20130701).
    Sturm, Dennis
    KTH, School of Technology and Health (STH), Centres, Centre for Technology in Medicine and Health, CTMH.
    ExecutiveSummary of AugmentIT: A Smart Phone App that generates kinematic feedback based on augmented reality data e.g. vidoeo and IMU (or other sensor) data2012Other (Other (popular science, discussion, etc.))
  • 134.
    Åkerberg, Mathias
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Tibbling, Anders
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Säker identitetshantering på internet: Att minimera bedrägerier och öka konsumentens säkerhet och inflytande vid e-handel2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There's a high risk that an unauthorized party can gain access to and use a consumer's iden-tity. This while the ability to control how and when a personal identity is used is small. The question to be answered were regarding how identity theft and online fraud could be mi-nimized and give the consumers a greater influence and more control over the management of their identity online.

    The goal was to centralize and establish a common approach for identity management on-line, with greater benefits for consumers. Through central service individual consumers would be able to set conditions for which online shops and services would be able to access their identities and grant access in each specific transaction. This would remove the need for non-central control of identities and as a result remove the need for independent storage of identity information.

    The solution would result in a system model with the potential to authenticate the consu-mer, managing conditions for how individual identity documents may be used online and to provide the consumer with a online history by sending notifications of events that has occurred with regard to a specific identity.

    A prototype was developed to demonstrate the basic functionality in practice. This included the functionality to authenticate the consumer with Mobile BankID, send notifications about events and check existing conditions regarding a specific identity. This prototype came to consist of a simplified system according to the model developed, an associated API, and two models representing an online store and a payment provider that would utilize the functionality of the system by calling the API.

    The proposed solution was evaluated through two interviews with experts in the fields of IT Security and e-commerce. The conclusion was that identity fraud would probably drop drastically and the individual consumer influence and awareness would be fortified. The main reason for this was considered to be primarily through the consistent and standardized way for authentication of and communication with the consumer. This would remove the individual risk for online services.

    The challenge with this proposed solution is believed to be getting consumers, online re-tailers and payment providers to accept a central solution instead of relying on internally developed and disconnected solution.

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