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  • 1901.
    Melchert, Jonas
    et al.
    Örebro University, Department of Technology.
    Coradeschi, Silvia
    Örebro University, Department of Technology.
    Loutfi, Amy
    Örebro University, Department of Technology.
    Spatial Relations for Perceptual Anchoring2007In: Proceedings of AISB'07, 2007, p. 459-463Conference paper (Other academic)
    Abstract [en]

    In this work we show how a mobile robot can use spatial information of objects to improve communication with humans and other devices located in an intelligent environment. In particular, this work focuses on using spatial relations to facilitate the creation of a connection between symbolic and perceptual representation that refer to the same physical object (anchoring). We extend an anchoring framework to include a set of binary spatial relations which can then be used to exchange information about objects with a human user. To illustrate the performance of the framework, a number of scenarios are presented using a mobile robot. These scenarios are a first step towards the goal of having mobile robots integrated in an intelligent environment and communicating with human users.

  • 1902.
    Melin, Ulf
    et al.
    Linköpings universitet.
    Axelsson, Karin
    Örebro University, Swedish Business School at Örebro University.
    Managing e-service development: comparing two e-government case studies2009In: Transforming Government - People, Process and Policy, ISSN 1750-6166, Vol. 3, no 3, p. 248-270Article in journal (Refereed)
    Abstract [en]

    Purpose – To contribute to a better understanding of the progress and the success vs. failure in e-government development, based on case studies of two inter-organizational e-service projects.

    Design/Methodology/Approach – The analysis in the paper is made from a) an e-government systems development life-cycle perspective and b) a challenge and success factor perspective. The point of departure is theory and a comparative analysis of two e-government projects.

    Findings – The main results in this paper are 1) a combination of perspectives (in a project stage and analysis grid) that can serve as a support when managing e-service development and 2) a set of identified crucial success factors within an inter-organizational e-government project including project manager skills and position in the agency organization as well as when and how systems maintenance issues are introduced into a project. Existing theory and perspectives are also criticised based on the present study.

    Practical implications – Lessons to learn from a challenge and success factors perspective in two different e-government projects, and suggestions to revise an e-government development life-cycle in order to perform a better practice in the field. The revised/developed project stage and analysis grid presented in the paper is one way to deal with the challenges related to the management of e-service development in the public sector.

    Originality/value – This paper addresses a number of challenges of complexity and risk that e-government initiatives face. It is not an easy matter to realize such initiatives’ potential. A key research issue for the e-government field, as well as the information systems field in general, is to understand why some projects progress to success while others end in failure. This is the niche for the present paper.

  • 1903.
    Melin, Ulf
    et al.
    Linköpings universitet.
    Axelsson, Karin
    Örebro University, Swedish Business School at Örebro University.
    Wedlund, Tommy
    Linköpings universitet.
    Project-based Learning: An Emergent Framework for Designing Courses2009In: Information systems education journal, ISSN 1545-679X, Vol. 7, p. 34-Article in journal (Refereed)
    Abstract [en]

    In this paper we elaborate on a framework, a set of guidelines, for teachers when designing project based courses. The emergent framework presented in this paper will focus on six themes: (1) overall course design, (2) project task, (3) project group, (4) examination, (5) feedback and (6) course evaluation and improvement and is initially grounded in theory and practice. The framework elaborated in this paper should support teachers' development of a professional autonomy within the norms of a professional group and an active curriculum.

  • 1904.
    Memedi, Mevludin
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    A mobile-based system can assess Parkinson's disease symptoms from home environments of patients2014In: Neurologi i Sverige, ISSN 2000-8538, no 3, p. 24-28Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    Treatment of Parkinson's disease (PD) patients involves major challenges like the large within- and between-patient variability in symptom profiles and the emergence of motor complications. As PD progresses, the symptoms develop slowly and they represent a significant source of disability in advanced patients. During evaluation of treatments and symptoms, both the physician- and patient-oriented outcomes offer complementary information. In addition, quantitative assessments of symptoms using sensing technologies can potentially complement and enhance both patient and clinician perspectives. At Högskolan Dalarna, the Lecturer Mevludin Memedi has developed a telemetry system that assesses symptoms via analysis of self-assessments and motor tests to objectively measure disease-related outcomes and to improve the management of PD.

  • 1905.
    Memedi, Mevludin
    Örebro University, School of Science and Technology. Dalarna University, Falun, Sweden.
    Mobile systems for monitoring Parkinson's disease2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A challenge for the clinical management of Parkinson's disease (PD) is the large within- and between-patient variability in symptom profiles as well as the emergence of motor complications which represent a significant source of disability in patients. This thesis deals with the development and evaluation of methods and systems for supporting the management of PD by using repeated measures, consisting of subjective assessments of symptoms and objective assessments of motor function through fine motor tests (spirography and tapping), collected by means of a telemetry touch screen device.

    One aim of the thesis was to develop methods for objective quantification and analysis of the severity of motor impairments being represented in spiral drawings and tapping results. This was accomplished by first quantifying the digitized movement data with time series analysis and then using them in data-driven modelling for automating the process of assessment of symptom severity. The objective measures were then analysed with respect to subjective assessments of motor conditions. Another aim was to develop a method for providing comparable information content as clinical rating scales by combining subjective and objective measures into composite scores, using time series analysis and data driven methods. The scores represent six symptom dimensions and an overall test score for reflecting the global health condition of the patient. In addition, the thesis presents the development of a web-based system for providing a visual representation of symptoms over time allowing clinicians to remotely monitor the symptom profiles of their patients. The quality of the methods was assessed by reporting different metrics of validity, reliability and sensitivity to treatment interventions and natural PD progression over time.

    Results from two studies demonstrated that the methods developed for the fine motor tests had good metrics indicating that they are appropriate to quantitatively and objectively assess the severity of motor impairments of PD patients. The fine motor tests captured different symptoms; spiral drawing impairment and tapping accuracy related to dyskinesias (involuntary movements) whereas tapping speed related to bradykinesia (slowness of movements). A longitudinal data analysis indicated that the six symptom dimensions and the overall test score contained important elements of information of the clinical scales and can be used to measure effects of PD treatment interventions and disease progression. A usability evaluation of the web-based system showed that the information presented in the system was comparable to qualitative clinical observations and the system was recognized as a tool that will assist in the management of patients.

    List of papers
    1. A new computer method for assessing drawing impairment in Parkinson's disease
    Open this publication in new window or tab >>A new computer method for assessing drawing impairment in Parkinson's disease
    Show others...
    2010 (English)In: Journal of Neuroscience Methods, ISSN 0165-0270, E-ISSN 1872-678X, Vol. 190, no 1, p. 143-148Article in journal (Refereed) Published
    Abstract [en]

    A test battery, consisting of self-assessments and motor tests (tapping and spiral drawing tasks) was used on 9482 test occasions by 62 patients with advanced Parkinson's disease (PD) in a telemedicine setting. On each test occasion, three Archimedes spirals were traced. A new computer method, using wavelet transforms and principal component analysis processed the spiral drawings to generate a spiral score. In a web interface, two PD specialists rated drawing impairment in spiral drawings from three random test occasions per patient, using a modification of the Bain & Findley 10-category scale. A standardised manual rating was defined as the mean of the two raters’ assessments. Bland-Altman analysis was used to evaluate agreement between the spiral score and the standardised manual rating. Another selection of spiral drawings was used to estimate the Spearman rank correlations between the raters (r = 0.87), and between the mean rating and the spiral score (r = 0.89). The 95% confidence interval for the method's prediction errors was ±1.5 scale units, which was similar to the differences between the human raters. In conclusion, the method could assess PD-related drawing impairments well comparable to trained raters.

    Place, publisher, year, edition, pages
    Amsterdam: Elsevier, 2010
    Keywords
    Test battery, Home environment, Motor test, Tremor, Dyskinesia, Spiral drawing, Drawing impairment, Wavelet transform, Principal component analysis, Involuntary movement, Movement disorders, Motor fluctuations, Parkinson's disease, Telemedicine
    National Category
    Neurosciences Biochemistry and Molecular Biology
    Research subject
    Biochemistry
    Identifiers
    urn:nbn:se:oru:diva-20464 (URN)10.1016/j.jneumeth.2010.04.027 (DOI)000279888800019 ()20438759 (PubMedID)2-s2.0-77953725166 (Scopus ID)
    Available from: 2011-12-02 Created: 2011-12-02 Last updated: 2018-01-12Bibliographically approved
    2. Automatic and objective assessment of alternating tapping performance in parkinson’s disease
    Open this publication in new window or tab >>Automatic and objective assessment of alternating tapping performance in parkinson’s disease
    Show others...
    2013 (English)In: Sensors, E-ISSN 1424-8220, Vol. 13, no 12, p. 16965-16984Article in journal (Refereed) Published
    Abstract [en]

    This paper presents the development and evaluation of a method for enabling quantitative and automatic scoring of alternating tapping performance of patients with Parkinson‟s disease (PD). Ten healthy elderly subjects and 95 patients in different clinical stages of PD have utilized a touch-pad handheld computer to perform alternate tapping tests in their home environments. First, a neurologist used a web-based system to visually assess impairments in four tapping dimensions („speed‟, „accuracy‟, „fatigue‟ and „arrhythmia‟) and a global tapping severity (GTS). Second, tapping signals were processed with time series analysis and statistical methods to derive 24 quantitative parameters. Third, principal component analysis was used to reduce the dimensions of these parameters and to obtain scores for the four dimensions. Finally, a logistic regressionclassifier was trained using a 10-fold stratified cross-validation to map the reduced parameters to the corresponding visually assessed GTS scores. Results showed that the computed scores correlated well to visually assessed scores and were significantly different across Unified Parkinson‟s Disease Rating Scale scores of upper limb motor performance. In addition, they had good internal consistency, had good ability to discriminate between healthy elderly and patients in different disease stages, had good sensitivity to treatment interventions and could reflect the natural disease progression over time. In conclusion, the automatic method can be useful to objectively assess the tapping performance ofPD patients and can be included in telemedicine tools for remote monitoring of tapping.

    Place, publisher, year, edition, pages
    Basel: MDPI AG, 2013
    Keywords
    alternating tapping; touch-pad; handheld computer; telemedicine; Parkinson‟s disease; remote monitoring; automatic assessment; objective assessment; visual assessment
    National Category
    Computer Sciences Chemical Sciences
    Research subject
    Computer Science
    Identifiers
    urn:nbn:se:oru:diva-33095 (URN)10.3390/s131216965 (DOI)000330220600061 ()2-s2.0-84890107007 (Scopus ID)
    Funder
    Swedish Research Council
    Note

    Funding Agencies:

    Nordforce Technology AB, Stockholm, Sweden

    Animech AB, Uppsala, Sweden

    Dalarna University, Borlänge, Sweden

    Available from: 2014-01-14 Created: 2014-01-14 Last updated: 2022-02-10Bibliographically approved
    3. Spiral drawing during self-rated dyskinesia is more impaired than during self-rated off
    Open this publication in new window or tab >>Spiral drawing during self-rated dyskinesia is more impaired than during self-rated off
    2013 (English)In: Parkinsonism & Related Disorders, ISSN 1353-8020, E-ISSN 1873-5126, Vol. 19, no 5, p. 553-556Article in journal (Refereed) Published
    Abstract [en]

    Objective: The purpose of this study was to examine repeated measures of fine motor function in relation to self-assessed motor conditions in Parkinson's disease (PD).

    Methods: One-hundred PD patients, 65 with advanced PD and 35 patients with different disease stages have utilized a test battery in a telemedicine setting. On each test occasion, they initially self-assessed their motor condition (from 'very off' to 'very dyskinetic') and then performed a set of fine motor tests (tapping and spiral drawings).

    Results: The motor tests scores were found to be the best during self-rated On. Self-rated dyskinesias caused more impaired spiral drawing performance (mean = 9.8% worse, P < 0.001) but at the same time tapping speed was faster (mean = 5.0% increase, P < 0.001), compared to scores in self-rated Off.

    Conclusions: The fine motor tests of the test battery capture different symptoms; the spiral impairment primarily relates to dyskinesias whereas the tapping speed captures the Off symptoms.

    Keywords
    Spiral drawing, Dyskinesia, Tapping, Bradykinesia, Self-assessment, Telemedicine
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering Neurology
    Research subject
    Electrical Engineering
    Identifiers
    urn:nbn:se:oru:diva-29045 (URN)10.1016/j.parkreldis.2013.01.011 (DOI)000317455800010 ()2-s2.0-84875551765 (Scopus ID)
    Available from: 2013-05-20 Created: 2013-05-17 Last updated: 2021-04-15Bibliographically approved
    4. Combined fine-motor tests and self-assessments for remote detection of motor fluctuations
    Open this publication in new window or tab >>Combined fine-motor tests and self-assessments for remote detection of motor fluctuations
    2013 (English)In: Recent Patents on Biomedical Engineering, ISSN 1874-7647, Vol. 6, no 2, p. 127-135Article in journal (Refereed) Published
    Abstract [en]

    A major problem with the clinical management of fluctuating movement disorders, e.g. Parkinson’s disease (PD), is the large variability in manifestation of symptoms among patients. In this condition, frequent measurements which account for both patient-reported and objective assessments are needed in order to capture symptom fluctuations, with the purpose to optimize therapy. The main focus of this paper is to present a mobile-based system for enabling remote monitoring of PD patients from their home environment conditions. The system consists of a patient diary section for collecting patient-based self-assessments, a motor test section for collecting fine motor movements through upper limb motor tests, and a scheduler for restricting operation to a multitude of predetermined limited time intervals. The system processes and compiles time series data into different summary scores representing symptom severity. In addition, the paper presents a review of recent inventions which were filed after year 2000 in the field of telemedicine applications. The review includes a summary of systems and methods which enable remote symptom assessments of patients, not necessarily suffering from movement disorders, through repeated measurements and which take into account their subjective and/or objective health indicators. The findings conclude that there are a small number of inventions which collect subjective and objective health measures in telemedicine settings. Consequently, there is a lack of mechanisms that combine these two types of information into scores to provide a more in-depth assessment of the patient’s general health, their motor and non-motor symptom fluctuations and treatment effects. The paper also provides a discussion concerning different approaches for analyzing and combining subjective and objective measures, and handling data from longitudinal studies.

    Place, publisher, year, edition, pages
    Bentham Science Publishers, 2013
    Keywords
    remote patient monitoring, Parkinson’s disease, subjective, objective, telemedicine
    National Category
    Computer Sciences
    Research subject
    Computer Science
    Identifiers
    urn:nbn:se:oru:diva-33941 (URN)10.2174/18747647113069990001 (DOI)2-s2.0-84882786800 (Scopus ID)
    Note

    Swedish Knowledge Foundation, Abbott Product Operations AG (nowAbbVie), Nordforce Technology AB and Animech AB are gratefully acknowledged for the financial support they have extended within the frameworks of the E-MOTIONS and PAULINA projects.

    Available from: 2014-02-26 Created: 2014-02-26 Last updated: 2018-09-12Bibliographically approved
    5. A web application for follow-up of results from a mobile device test battery for Parkinson's disease patients
    Open this publication in new window or tab >>A web application for follow-up of results from a mobile device test battery for Parkinson's disease patients
    Show others...
    2011 (English)In: Computer Methods and Programs in Biomedicine, ISSN 0169-2607, E-ISSN 1872-7565, Vol. 104, no 2, p. 219-226Article in journal (Refereed) Published
    Abstract [en]

    This paper describes a web-based system for enabling remote monitoring of patients with Parkinson's disease (PD) and supporting clinicians in treating their patients. The system consists of a patient node for subjective and objective data collection based on a handheld computer, a service node for data storage and processing, and a web application for data presentation. Using statistical and machine learning methods, time series of raw data are summarized into scores for conceptual symptom dimensions and an “overall test score” providing a comprehensive profile of patient's health during a test period of about one week. The handheld unit was used quarterly or biannually by 65 patients with advanced PD for up to four years at nine clinics in Sweden. The IBM Computer System Usability Questionnaire was administered to assess nurses’ satisfaction with the web application. Results showed that a majority of the nurses were quite satisfied with the usability although a sizeable minority were not. Our findings support that this system can become an efficient tool to easily access relevant symptom information from the home environment of PD patients.

    Place, publisher, year, edition, pages
    Amsterdam: Elsevier, 2011
    Keywords
    Parkinson's disease, Test battery, Web application, Decision support, Remote patient monitoring, Telemedicine, Principal component analysis
    National Category
    Information Systems
    Research subject
    Computer and Systems Science
    Identifiers
    urn:nbn:se:oru:diva-20469 (URN)10.1016/j.cmpb.2011.07.017 (DOI)000296945100024 ()21872355 (PubMedID)2-s2.0-80054120422 (Scopus ID)
    Note

    7th IFAC Symposium on Modelling and Control in Biomedical Systems

    Available from: 2011-12-02 Created: 2011-12-02 Last updated: 2018-01-12Bibliographically approved
    6. Self-assessments and motor test via telemetry in a 36-month levodopa-carbidopa intestinal gelinfusion trial
    Open this publication in new window or tab >>Self-assessments and motor test via telemetry in a 36-month levodopa-carbidopa intestinal gelinfusion trial
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Computer Sciences Neurology
    Research subject
    Computer Science; Neurology
    Identifiers
    urn:nbn:se:oru:diva-33942 (URN)
    Note

    Objective: The aim of this study was to investigate if a telemetry test battery can be used to measure effects of Parkinson’s disease (PD) treatment intervention and disease progression.

    Methods: Sixty-five patients diagnosed with advanced PD were recruited in an openlongitudinal 36-month study; 35 treated with levodopa-carbidopa intestinal gel (LCIG) and 30 were candidates for switching from oral PD treatment to LCIG. They utilized a test battery, consisting of self-assessments of symptoms and fine motor tests (tapping and spiral drawings), four times per day in their homes during week-long test periods. The repeated measurements were summarized into an overall test score (OTS) to represent the global condition of the patient during a test period. Clinical assessments included ratings on Unified PD Rating Scale (UPDRS) and 39-item PD Questionnaire (PDQ-39) scales.

    Results: In LCIG-naïve patients, mean OTS compared to baseline was significantly improved from the first test period on LCIG treatment until month 24. In LCIG non-naïve patients, there were no significant changes in mean OTS, except at month 36 (P<0.01). The OTS correlated adequately with total UPDRS (rho = 0.59) and total PDQ-39 (0.59).

    Conclusions: PD symptoms can be remotely monitored over time with this test battery. The trends of the test scores were similar to the trends of clinical rating scores. Correlations between OTS and clinical rating scales were adequate indicating that the test battery contains important elements of the information of the well-established scales.

    Available from: 2014-02-26 Created: 2014-02-26 Last updated: 2018-01-11Bibliographically approved
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  • 1906.
    Memedi, Mevludin
    Örebro University, School of Science and Technology.
    Mobile systems for monitoring Parkinson's disease2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents the development and evaluation of IT-based methods and systems for supporting assessment of symptoms and enabling remote monitoring of Parkinson‟s disease (PD) patients. PD is a common neurological disorder associated with impaired body movements. Its clinical management regarding treatment outcomes and follow-up of patients is complex. In order to reveal the full extent of a patient‟s condition, there is a need for repeated and time-stamped assessments related to both patient‟s perception towards common symptoms and motor function. In this thesis, data from a mobile device test battery, collected during a three year clinical study, was used for the development and evaluation of methods. The data was gathered from a series of tests, consisting of selfassessments and motor tests (tapping and spiral drawing). These tests were carried out repeatedly in a telemedicine setting during week-long test periods. One objective was to develop a computer method that would process tracedspiral drawings and generate a score representing PD-related drawing impairments. The data processing part consisted of using the discrete wavelet transform and principal component analysis. When this computer method was evaluated against human clinical ratings, the results showed that it could perform quantitative assessments of drawing impairment in spirals comparatively well. As a part of this objective, a review of systems and methods for detecting the handwriting and drawing impairment using touch screens was performed. The review showed that measures concerning forces, accelerations, and radial displacements were the most important ones in detecting fine motor movement anomalies. Another objective of this thesis work was to design and evaluate an information system for delivering assessment support information to the treating clinical staff for monitoring PD symptoms in their patients. The system consisted of a patient node for data collection based on the mobile device test battery, a service node for data storage and processing, and a web application for data presentation. A system module was designed for compiling the test battery time series into summary scores on a test period level. The web application allowed adequate graphic feedback of the summary scores to the treating clinical staff. The evaluation results for this integrated system indicate that it can be used as a tool for frequent PD symptom assessments in home environments.

    List of papers
    1. Methods for detection of handwriting/drawing impairment using inputs from touch screens
    Open this publication in new window or tab >>Methods for detection of handwriting/drawing impairment using inputs from touch screens
    2011 (English)In: Recent Patents on Signal Processing, ISSN 1877-6124, Vol. 1, no 2, p. 156-162Article in journal (Refereed) Published
    Abstract [en]

    Fine motor dysfunction in patients with movement disorders, such as Parkinson’s disease, is characterized by slowness of movements, decrease of reaction time and involuntary movements. In this article, recent patents on detecting and assessing the said dysfunction are reviewed; their implementation in telemedicine settings, design considerations and ability to assist in dose and time adjustments are discussed. These patents explain application of signal processing techniques in analysis and interpretation of digitized handwriting/drawing information of individuals based on data gathered using touch screens. The study reveals that measures concerning forces, accelerations and radial displacements are the most relevant measurements to detect fine movement anomalies. These findings demonstrate that digitized analysis of handwriting/drawing movements may be useful in clinical trials evaluating fine motor control. This review further depicts the role of employing event-based data acquisition and signal processing techniques suitable for nonstationary signals, such as Wavelet transform, in systems for patient home-monitoring.

    Place, publisher, year, edition, pages
    Bussum: Bentham Science Publishers, 2011
    Keywords
    Drawing, fine motor impairment, Fourier transform, handwriting, home monitoring, Parkinson’s disease, touch screens, Wavelet transform
    National Category
    Signal Processing
    Research subject
    Signal Processing
    Identifiers
    urn:nbn:se:oru:diva-20463 (URN)10.2174/2210686311101020156 (DOI)
    Available from: 2011-12-02 Created: 2011-12-02 Last updated: 2018-02-15Bibliographically approved
    2. A new computer method for assessing drawing impairment in Parkinson's disease
    Open this publication in new window or tab >>A new computer method for assessing drawing impairment in Parkinson's disease
    Show others...
    2010 (English)In: Journal of Neuroscience Methods, ISSN 0165-0270, E-ISSN 1872-678X, Vol. 190, no 1, p. 143-148Article in journal (Refereed) Published
    Abstract [en]

    A test battery, consisting of self-assessments and motor tests (tapping and spiral drawing tasks) was used on 9482 test occasions by 62 patients with advanced Parkinson's disease (PD) in a telemedicine setting. On each test occasion, three Archimedes spirals were traced. A new computer method, using wavelet transforms and principal component analysis processed the spiral drawings to generate a spiral score. In a web interface, two PD specialists rated drawing impairment in spiral drawings from three random test occasions per patient, using a modification of the Bain & Findley 10-category scale. A standardised manual rating was defined as the mean of the two raters’ assessments. Bland-Altman analysis was used to evaluate agreement between the spiral score and the standardised manual rating. Another selection of spiral drawings was used to estimate the Spearman rank correlations between the raters (r = 0.87), and between the mean rating and the spiral score (r = 0.89). The 95% confidence interval for the method's prediction errors was ±1.5 scale units, which was similar to the differences between the human raters. In conclusion, the method could assess PD-related drawing impairments well comparable to trained raters.

    Place, publisher, year, edition, pages
    Amsterdam: Elsevier, 2010
    Keywords
    Test battery, Home environment, Motor test, Tremor, Dyskinesia, Spiral drawing, Drawing impairment, Wavelet transform, Principal component analysis, Involuntary movement, Movement disorders, Motor fluctuations, Parkinson's disease, Telemedicine
    National Category
    Neurosciences Biochemistry and Molecular Biology
    Research subject
    Biochemistry
    Identifiers
    urn:nbn:se:oru:diva-20464 (URN)10.1016/j.jneumeth.2010.04.027 (DOI)000279888800019 ()20438759 (PubMedID)2-s2.0-77953725166 (Scopus ID)
    Available from: 2011-12-02 Created: 2011-12-02 Last updated: 2018-01-12Bibliographically approved
    3. A web application for follow-up of results from a mobile device test battery for Parkinson's disease patients
    Open this publication in new window or tab >>A web application for follow-up of results from a mobile device test battery for Parkinson's disease patients
    Show others...
    2011 (English)In: Computer Methods and Programs in Biomedicine, ISSN 0169-2607, E-ISSN 1872-7565, Vol. 104, no 2, p. 219-226Article in journal (Refereed) Published
    Abstract [en]

    This paper describes a web-based system for enabling remote monitoring of patients with Parkinson's disease (PD) and supporting clinicians in treating their patients. The system consists of a patient node for subjective and objective data collection based on a handheld computer, a service node for data storage and processing, and a web application for data presentation. Using statistical and machine learning methods, time series of raw data are summarized into scores for conceptual symptom dimensions and an “overall test score” providing a comprehensive profile of patient's health during a test period of about one week. The handheld unit was used quarterly or biannually by 65 patients with advanced PD for up to four years at nine clinics in Sweden. The IBM Computer System Usability Questionnaire was administered to assess nurses’ satisfaction with the web application. Results showed that a majority of the nurses were quite satisfied with the usability although a sizeable minority were not. Our findings support that this system can become an efficient tool to easily access relevant symptom information from the home environment of PD patients.

    Place, publisher, year, edition, pages
    Amsterdam: Elsevier, 2011
    Keywords
    Parkinson's disease, Test battery, Web application, Decision support, Remote patient monitoring, Telemedicine, Principal component analysis
    National Category
    Information Systems
    Research subject
    Computer and Systems Science
    Identifiers
    urn:nbn:se:oru:diva-20469 (URN)10.1016/j.cmpb.2011.07.017 (DOI)000296945100024 ()21872355 (PubMedID)2-s2.0-80054120422 (Scopus ID)
    Note

    7th IFAC Symposium on Modelling and Control in Biomedical Systems

    Available from: 2011-12-02 Created: 2011-12-02 Last updated: 2018-01-12Bibliographically approved
    Download full text (pdf)
    fulltext_Prot
  • 1907.
    Memedi, Mevludin
    et al.
    Örebro University, Örebro University School of Business.
    Aghanavesi, Somayeh
    Computer Engineering, Dalarna University, Sweden.
    A partial least-squares regression model to measure Parkinson’s disease motor states using smartphone data2020In: Proceedings of the 53rd Hawaii International Conference on System Sciences | 2020, Maui, Hawaii: HCSS , 2020, p. 1056-1062Conference paper (Refereed)
    Abstract [en]

    Design choices related to development of data- driven models significantly impact or degrade predictive performance of the models. One of the essential steps during development and evaluation of such models is the choice of feature selection and dimension reduction techniques. That is imperative especially in cases dealing with multimodal data gathered from different sources. In this paper, we will investigate the behavior of Partial Least Squares (PLS) regression for dimension reduction and prediction of motor states of Parkinson’s disease (PD) patients, using upper limb motor data gathered by means of a smartphone. The results in terms of correlations between smartphone-based and clinician-derived scores were compared to a previous study using the same data where principal component analysis (PCA) and support vector machines (SVM) were used. The findings from this study show that PLS is superior in terms of prediction performance of motor states in PD than combining PCA and SVM. This indicates that PLS could be considered as a useful methodology in problems where data-driven analysis is needed.

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    A partial least-squares regression model to measure Parkinson’s disease motor states using smartphone data
  • 1908.
    Memedi, Mevludin
    et al.
    Örebro University, Örebro University School of Business.
    Aghanavesi, Somayeh
    th Computer Engineering, Dalarna University, Sweden.
    Bergquist, Filip
    Department of Pharmacology, Gothenburg University, Sweden.
    Nyholm, Dag
    Department of Neuroscience, Uppsala University, Sweden (.
    Senek, Marina
    Department of Neuroscience, Uppsala University, Sweden.
    A multimodal sensor fusion platform for objective assessment of motor states in Parkinson's disease2019In: IEEE-EMBS INTERNATIONAL CONFERENCE ON BIOMEDICAL AND HEALTH INFORMATICS (BHI 19), 2019Conference paper (Refereed)
    Abstract [en]

    This study proposes a platform to objectively assess motor states in Parkinson’s disease (PD) using sensor technology and machine learning. The platform uses sensor information gathered during standardized motor tasks and fuses them in a data-driven manner to produce an index representing motor states of the patients. After investigating clinimetric properties of the platform it was found that the platform had good validity and responsiveness to treatment, which are essential for developing systems to individualize treatments.

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    A multimodal sensor fusion platform for objective assessment of motor states in Parkinson’s disease
  • 1909.
    Memedi, Mevludin
    et al.
    Örebro University, Örebro University School of Business. Datateknik, Högskolan Dalarna, Borlänge, Sweden.
    Aghanavesi, Somayeh
    Datateknik, Högskolan Dalarna, Borlänge, Sweden.
    Westin, Jerker
    Datateknik, Högskolan Dalarna, Borlänge, Sweden.
    Digital spiral analysis for objective assessment of fine motor timing variability in Parkinson's disease2015Conference paper (Other academic)
    Abstract [en]

    OBJECTIVES: To develop a method for objective assessment of fine motor timing variability in Parkinson’s disease (PD) patients, using digital spiral data gathered by a touch screen device.

    BACKGROUND: A retrospective analysis was conducted on data from 105 subjects including65 patients with advanced PD (group A), 15 intermediate patients experiencing motor fluctuations (group I), 15 early stage patients (group S), and 10 healthy elderly subjects (HE) were examined. The subjects were asked to perform repeated upper limb motor tasks by tracing a pre-drawn Archimedes spiral as shown on the screen of the device. The spiral tracing test was performed using an ergonomic pen stylus, using dominant hand. The test was repeated three times per test occasion and the subjects were instructed to complete it within 10 seconds. Digital spiral data including stylus position (x-ycoordinates) and timestamps (milliseconds) were collected and used in subsequent analysis. The total number of observations with the test battery were as follows: Swedish group (n=10079), Italian I group (n=822), Italian S group (n = 811), and HE (n=299).

    METHODS: The raw spiral data were processed with three data processing methods. To quantify motor timing variability during spiral drawing tasks Approximate Entropy (APEN) method was applied on digitized spiral data. APEN is designed to capture the amount of irregularity or complexity in time series. APEN requires determination of two parameters, namely, the window size and similarity measure. In our work and after experimentation, window size was set to 4 and similarity measure to 0.2 (20% of the standard deviation of the time series). The final score obtained by APEN was normalized by total drawing completion time and used in subsequent analysis. The score generated by this method is hence on denoted APEN. In addition, two more methods were applied on digital spiral data and their scores were used in subsequent analysis. The first method was based on Digital Wavelet Transform and Principal Component Analysis and generated a score representing spiral drawing impairment. The score generated by this method is hence on denoted WAV. The second method was based on standard deviation of frequency filtered drawing velocity. The score generated by this method is hence on denoted SDDV. Linear mixed-effects (LME) models were used to evaluate mean differences of the spiral scores of the three methods across the four subject groups. Test-retest reliability of the three scores was assessed after taking mean of the three possible correlations (Spearman’s rank coefficients) between the three test trials. Internal consistency of the methods was assessed by calculating correlations between their scores.

    RESULTS: When comparing mean spiral scores between the four subject groups, the APEN scores were different between HE subjects and three patient groups (P=0.626 for S group with 9.9% mean value difference, P=0.089 for I group with 30.2%, and P=0.0019 for A group with 44.1%). However, there were no significant differences in mean scores of the other two methods, except for the WAV between the HE and A groups (P<0.001). WAV and SDDV were highly and significantly correlated to each other with a coefficient of 0.69. However, APEN was not correlated to neither WAV nor SDDV with coefficients of 0.11 and 0.12, respectively. Test-retest reliability coefficients of the three scores were as follows: APEN (0.9), WAV(0.83) and SD-DV (0.55).

    CONCLUSIONS: The results show that the digital spiral analysis-based objective APEN measure is able to significantly differentiate the healthy subjects from patients at advanced level. In contrast to the other two methods (WAV and SDDV) that are designed to quantify dyskinesias (over-medications), this method can be useful for characterizing Off symptoms in PD. The APEN was not correlated to none of the other two methods indicating that it measures a different construct of upper limb motor function in PD patients than WAV and SDDV. The APEN also had a better test-retest reliability indicating that it is more stable and consistent over time than WAV and SDDV.

  • 1910.
    Memedi, Mevludin
    et al.
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Aghanavesi, Somayeh
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Westin, Jerker
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Objective quantification of Parkinson's disease upper limb motor timing variability using spirography2015Conference paper (Refereed)
    Abstract [en]

    Objective quantification of the upper limb motor timing variability of Parkinson’s disease (PD) patients was evaluated using traces of spirals by groups of patients at different disease stages, stable (S), intermediate (I), advanced (A) and a healthy elderly (HE) group. The approximate entropy (APEN) method of quantifying motor timing variability in time series was applied to capture the amount of irregularity during the spiral drawing process. The APEN score was then normalized by total drawing completion time and used in subsequent analysis. In addition, two previously published methods (WAV and SDDV) were applied on the spiral data. Comparing subject groups’ APEN mean scores, they were found to be significantly different from HE group, for group A (P<0.001) indicating this method’s ability in distinguishing patients at advanced disease stage. Comparing the three methods’ ability to track response to advanced treatment, APEN scores were all significantly different between base-line and levodopa-carbidopa intestinal gel (LCIG) treatment, during the 36 month study period as opposed to WAV and SDDV as they were not significantly improving for all periods. APEN scores were weakly correlated to WAV and SDDV, indicating that they measure different aspects of symptom severity.

  • 1911.
    Memedi, Mevludin
    et al.
    Örebro University, School of Science and Technology. School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Khan, Taha
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden; School of Innovation, Design and Technology, Mälardalen University, Västerås, Sweden.
    Grenholm, Peter
    Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Nyholm, Dag
    Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Westin, Jerker
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Automatic and objective assessment of alternating tapping performance in parkinson’s disease2013In: Sensors, E-ISSN 1424-8220, Vol. 13, no 12, p. 16965-16984Article in journal (Refereed)
    Abstract [en]

    This paper presents the development and evaluation of a method for enabling quantitative and automatic scoring of alternating tapping performance of patients with Parkinson‟s disease (PD). Ten healthy elderly subjects and 95 patients in different clinical stages of PD have utilized a touch-pad handheld computer to perform alternate tapping tests in their home environments. First, a neurologist used a web-based system to visually assess impairments in four tapping dimensions („speed‟, „accuracy‟, „fatigue‟ and „arrhythmia‟) and a global tapping severity (GTS). Second, tapping signals were processed with time series analysis and statistical methods to derive 24 quantitative parameters. Third, principal component analysis was used to reduce the dimensions of these parameters and to obtain scores for the four dimensions. Finally, a logistic regressionclassifier was trained using a 10-fold stratified cross-validation to map the reduced parameters to the corresponding visually assessed GTS scores. Results showed that the computed scores correlated well to visually assessed scores and were significantly different across Unified Parkinson‟s Disease Rating Scale scores of upper limb motor performance. In addition, they had good internal consistency, had good ability to discriminate between healthy elderly and patients in different disease stages, had good sensitivity to treatment interventions and could reflect the natural disease progression over time. In conclusion, the automatic method can be useful to objectively assess the tapping performance ofPD patients and can be included in telemedicine tools for remote monitoring of tapping.

  • 1912.
    Memedi, Mevludin
    et al.
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Nyholm, Dag
    Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Johansson, Anders
    Department of Clinical Neuroscience, Neurology, Karolinska Institutet, Stockholm, Sweden.
    Pålhagen, Sven
    Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.
    Willows, Thomas
    Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.
    Widner, Håkan
    Department of Neurology, Skåne University Hospital, Lund, Sweden.
    Linder, Jan
    Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden.
    Westin, Jerker
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Validity and Responsiveness of At-Home Touch Screen Assessments in Advanced Parkinson's Disease2015In: IEEE journal of biomedical and health informatics, ISSN 2168-2194, E-ISSN 2168-2208, Vol. 19, no 6, p. 1829-1834Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate if a telemetry test battery can be used to measure effects of Parkinson's disease (PD) treatment intervention and disease progression in patients with fluctuations. Sixty-five patients diagnosed with advanced PD were recruited in an open longitudinal 36-month study; 35 treated with levodopa-carbidopa intestinal gel (LCIG) and 30 were candidates for switching from oral PD treatment to LCIG. They utilized a test battery, consisting of self-assessments of symptoms and fine motor tests (tapping and spiral drawings), four times per day in their homes during week-long test periods. The repeated measurements were summarized into an overall test score (OTS) to represent the global condition of the patient during a test period. Clinical assessments included ratings on unified PD rating scale (UPDRS) and 39-item PD questionnaire (PDQ-39) scales. In LCIG-naïve patients, the mean OTS compared to baseline was significantly improved from the first test period on LCIG treatment until month 24. In LCIG-nonnaïve patients, there were no significant changes in the mean OTS until month 36. The OTS correlated adequately with total UPDRS (rho = 0.59) and total PDQ-39 (0.59). Responsiveness measured as effect size was 0.696 and 0.536 for OTS and UPDRS, respectively. The trends of the test scores were similar to the trends of clinical rating scores but the dropout rate was high. Correlations between OTS and clinical rating scales were adequate indicating that the test battery contains important elements of the information of well-established scales. The responsiveness and reproducibility were better for OTS than for total UPDRS.

  • 1913.
    Memedi, Mevludin
    et al.
    Örebro University, School of Science and Technology. School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Nyholm, Dag
    Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Johansson, Anders
    Department of Clinical Neuroscience, Neurology, Karolinska Institutet, Stockholm, Sweden.
    Pålhagen, Sven-Erik
    Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.
    Willows, Thomas
    Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.
    Widner, Håkan
    Department of Neurology, Skåne University Hospital, Lund, Sweden.
    Linder, Jan
    Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå Sweden.
    Westin, Jerker
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Self-assessments and motor test via telemetry in a 36-month levodopa-carbidopa intestinal gelinfusion trialManuscript (preprint) (Other academic)
  • 1914.
    Memedi, Mevludin
    et al.
    Örebro University, School of Science and Technology. Academy of Industry and Society, Computer Engineering, Dalarna University, Borlänge, Sweden.
    Nyholm, Dag
    Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Westin, Jerker
    Academy of Industry and Society, Computer Engineering, Dalarna University, Borlänge, Sweden.
    Combined fine-motor tests and self-assessments for remote detection of motor fluctuations2013In: Recent Patents on Biomedical Engineering, ISSN 1874-7647, Vol. 6, no 2, p. 127-135Article in journal (Refereed)
    Abstract [en]

    A major problem with the clinical management of fluctuating movement disorders, e.g. Parkinson’s disease (PD), is the large variability in manifestation of symptoms among patients. In this condition, frequent measurements which account for both patient-reported and objective assessments are needed in order to capture symptom fluctuations, with the purpose to optimize therapy. The main focus of this paper is to present a mobile-based system for enabling remote monitoring of PD patients from their home environment conditions. The system consists of a patient diary section for collecting patient-based self-assessments, a motor test section for collecting fine motor movements through upper limb motor tests, and a scheduler for restricting operation to a multitude of predetermined limited time intervals. The system processes and compiles time series data into different summary scores representing symptom severity. In addition, the paper presents a review of recent inventions which were filed after year 2000 in the field of telemedicine applications. The review includes a summary of systems and methods which enable remote symptom assessments of patients, not necessarily suffering from movement disorders, through repeated measurements and which take into account their subjective and/or objective health indicators. The findings conclude that there are a small number of inventions which collect subjective and objective health measures in telemedicine settings. Consequently, there is a lack of mechanisms that combine these two types of information into scores to provide a more in-depth assessment of the patient’s general health, their motor and non-motor symptom fluctuations and treatment effects. The paper also provides a discussion concerning different approaches for analyzing and combining subjective and objective measures, and handling data from longitudinal studies.

  • 1915.
    Memedi, Mevludin
    et al.
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Sadikov, Aleksander
    Artificial Intelligence Laboratory, Faculty of Computer and Information Science, University of Ljubljana, Ljubljana, Slovenia.
    Groznik, Vida
    Artificial Intelligence Laboratory, Faculty of Computer and Information Science, University of Ljubljana, Ljubljana, Slovenia.
    Zabkar, Jure
    Artificial Intelligence Laboratory, Faculty of Computer and Information Science, University of Ljubljana, Ljubljana, Slovenia.
    Mozina, Martin
    Artificial Intelligence Laboratory, Faculty of Computer and Information Science, University of Ljubljana, Ljubljana, Slovenia.
    Bergquist, Filip
    Department of Pharmacology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Johansson, Anders
    Department of Clinical Neuroscience, Neurology, Karolinska Institutet, Stockholm, Sweden.
    Haubenberger, Deitrich
    Clinical Trials Unit, Office of the Clinical Director, NINDS Intramural Research Program, National Institutes of Health, Bethesda MD, USA.
    Nyholm, Dag
    Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Automatic Spiral Analysis for Objective Assessment of Motor Symptoms in Parkinson’s Disease2015In: Sensors, E-ISSN 1424-8220, Vol. 15, no 9, p. 23727-23744Article in journal (Refereed)
    Abstract [en]

    A challenge for the clinical management of advanced Parkinson’s disease (PD) patients is the emergence of fluctuations in motor performance, which represents a significant source of disability during activities of daily living of the patients. There is a lack of objective measurement of treatment effects for in-clinic and at-home use that can provide an overview of the treatment response. The objective of this paper was to develop a method for objective quantification of advanced PD motor symptoms related to off episodes and peak dose dyskinesia, using spiral data gathered by a touch screen telemetry device. More specifically, the aim was to objectively characterize motor symptoms (bradykinesia and dyskinesia), to help in automating the process of visual interpretation of movement anomalies in spirals as rated by movement disorder specialists. Digitized upper limb movement data of 65 advanced PD patients and 10 healthy (HE) subjects were recorded as they performed spiral drawing tasks on a touch screen device in their home environment settings. Several spatiotemporal features were extracted from the time series and used as inputs to machine learning methods. The methods were validated against ratings on animated spirals scored by four movement disorder specialists who visually assessed a set of kinematic features and the motor symptom. The ability of the method to discriminate between PD patients and HE subjects and the test-retest reliability of the computed scores were also evaluated. Computed scores correlated well with mean visual ratings of individual kinematic features. The best performing classifier (Multilayer Perceptron) classified the motor symptom (bradykinesia or dyskinesia) with an accuracy of 84% and area under the receiver operating characteristics curve of 0.86 in relation to visual classifications of the raters. In addition, the method provided high discriminating power when distinguishing between PD patients and HE subjects as well as had good test-retest reliability. This study demonstrated the potential of using digital spiral analysis for objective quantification of PD-specific and/or treatment-induced motor symptoms.

  • 1916.
    Memedi, Mevludin
    et al.
    Örebro University, Örebro University School of Business. Datateknik, Högskolan Dalarna, Borlänge, Sweden.
    Sadikov, Aleksander
    Faculty of Information Science, Artificial Intelligence Laboratory, University of Ljubljana, Ljubljana, Slovenia.
    Groznik, Vida
    Faculty of Information Science, Artificial Intelligence Laboratory, University of Ljubljana, Ljubljana, Slovenia.
    Žabkar, Jure
    Faculty of Information Science, Artificial Intelligence Laboratory, University of Ljubljana, Ljubljana, Slovenia.
    Možina, Martin
    Faculty of Information Science, Artificial Intelligence Laboratory, University of Ljubljana, Ljubljana, Slovenia.
    Bergquist, Filip
    Department of Pharmacology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Johansson, Anders
    Neurology, Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
    Haubenberger, Dietrich
    NINDS Intramural Research Program, Clinical Trials Unit, National Institutes of Health, Bethesda MD, USA.
    Nyholm, Dag
    Neurology, Neuroscience, Uppsala University, Uppsala, Sweden.
    Automatic spiral analysis for objective assessment of motor symptoms in Parkinson's disease2015Conference paper (Other academic)
    Abstract [en]

    Objective: To develop a method for objective quantification of PD motor symptoms related to Off episodes and peak dose dyskinesias, using spiral data gathered by using a touch screen telemetry device. The aim was to objectively characterize predominant motor phenotypes (bradykinesia and dyskinesia), to help in automating the process of visual interpretation of movement anomalies in spirals as rated by movement disorder specialists.

    Background: A retrospective analysis was conducted on recordings from 65 patients with advanced idiopathic PD from nine different clinics in Sweden, recruited from January 2006 until August 2010. In addition to the patient group, 10 healthy elderly subjects were recruited. Upper limb movement data were collected using a touch screen telemetry device from home environments of the subjects. Measurements with the device were performed four times per day during week-long test periods. On each test occasion, the subjects were asked to trace pre-drawn Archimedean spirals, using the dominant hand. The pre-drawn spiral was shown on the screen of the device. The spiral test was repeated three times per test occasion and they were instructed to complete it within 10 seconds. The device had a sampling rate of 10Hz and measured both position and time-stamps (in milliseconds) of the pen tip.

    Methods: Four independent raters (FB, DH, AJ and DN) used a web interface that animated the spiral drawings and allowed them to observe different kinematic features during the drawing process and to rate task performance. Initially, a number of kinematic features were assessed including ‘impairment’, ‘speed’, ‘irregularity’ and ‘hesitation’ followed by marking the predominant motor phenotype on a 3-category scale: tremor, bradykinesia and/or choreatic dyskinesia. There were only 2 test occasions for which all the four raters either classified them as tremor or could not identify the motor phenotype. Therefore, the two main motor phenotype categories were bradykinesia and dyskinesia. ‘Impairment’ was rated on a scale from 0 (no impairment) to 10 (extremely severe) whereas ‘speed’, ‘irregularity’ and ‘hesitation’ were rated on a scale from 0 (normal) to 4 (extremely severe). The proposed data-driven method consisted of the following steps. Initially, 28 spatiotemporal features were extracted from the time series signals before being presented to a Multilayer Perceptron (MLP) classifier. The features were based on different kinematic quantities of spirals including radius, angle, speed and velocity with the aim of measuring the severity of involuntary symptoms and discriminate between PD-specific (bradykinesia) and/or treatment-induced symptoms (dyskinesia). A Principal Component Analysis was applied on the features to reduce their dimensions where 4 relevant principal components (PCs) were retained and used as inputs to the MLP classifier. Finally, the MLP classifier mapped these components to the corresponding visually assessed motor phenotype scores for automating the process of scoring the bradykinesia and dyskinesia in PD patients whilst they draw spirals using the touch screen device. For motor phenotype (bradykinesia vs. dyskinesia) classification, the stratified 10-fold cross validation technique was employed.

    Results: There were good agreements between the four raters when rating the individual kinematic features with intra-class correlation coefficient (ICC) of 0.88 for ‘impairment’, 0.74 for ‘speed’, 0.70 for ‘irregularity’, and moderate agreements when rating ‘hesitation’ with an ICC of 0.49. When assessing the two main motor phenotype categories (bradykinesia or dyskinesia) in animated spirals the agreements between the four raters ranged from fair to moderate. There were good correlations between mean ratings of the four raters on individual kinematic features and computed scores. The MLP classifier classified the motor phenotype that is bradykinesia or dyskinesia with an accuracy of 85% in relation to visual classifications of the four movement disorder specialists. The test-retest reliability of the four PCs across the three spiral test trials was good with Cronbach’s Alpha coefficients of 0.80, 0.82, 0.54 and 0.49, respectively. These results indicate that the computed scores are stable and consistent over time. Significant differences were found between the two groups (patients and healthy elderly subjects) in all the PCs, except for the PC3.

    Conclusions: The proposed method automatically assessed the severity of unwanted symptoms and could reasonably well discriminate between PD-specific and/or treatment-induced motor symptoms, in relation to visual assessments of movement disorder specialists. The objective assessments could provide a time-effect summary score that could be useful for improving decision-making during symptom evaluation of individualized treatment when the goal is to maximize functional On time for patients while minimizing their Off episodes and troublesome dyskinesias.

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    FULLTEXT01
  • 1917.
    Memedi, Mevludin
    et al.
    Örebro University, Örebro University School of Business. Computer Engineering, Dalarna University, Falun, Sweden.
    Thomas, Ilias
    Computer Engineering, Dalarna University, Falun, Sweden.
    Nyholm, Dag
    Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Westin, Jerker
    Computer Engineering, Dalarna University, Falun, Sweden.
    Senek, Marina
    Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Aghanavesi, Somayeh
    Computer Engineering, Dalarna University, Falun, Sweden.
    Medvedev, Alexander
    Information Technology, Uppsala University, Uppsala, Sweden.
    Askmark, Håkan
    Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Aquilonius, Sten-Magnus
    Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Bergquist, Filip
    Department of Pharmacology, University of Gothenburg, Gothenburg, Sweden.
    Constantinescu, Radu
    Departement of Clinical Neuroscience, University of Gothenburg, Gothenburg, Sweden.
    Ohlsson, Fredrik
    Acreo Swedish ICT, Stockholm, Sweden.
    Spira, Jack
    Sensidose AB, Sollentuna, Sweden.
    Lycke, Sara
    Cenvigo AB, Uppsala, Sweden.
    Ericsson, Anders
    Acreo Swedish ICT, Stockholm, Sweden.
    Construction of levodopa-response index from wearable sensors for quantifying Parkinson's disease motor functions2016Conference paper (Other academic)
    Abstract [en]

    The goal of this study was to investigate the feasibility of wrist worn motion sensors to objectively measure motor functions in Parkinson’s disease (PD). More specifically, the aim was to construct a sensor-based levodopa-response index (SBLRI) and evaluate its clinimetric properties (convergent validity and internal consistency). Nineteen advanced PD patients and 22 healthy controls were recruited in a single center, open label, single dose clinical trial in Sweden. The subjects performed standardized motor tasks while wearing one sensor on each wrist and one on each ankle. Each sensor unit consisted of three-dimensional accelerometer and gyroscope. The patients were video recorded and the videos were blindly rated by three independent movement disorder specialists. The clinical scores were given using the Treatment Response Scale (TRS) on a scale from -3 = ‘Very Off’ to 0 = ‘On’ to +3 = ‘Very dyskinetic’. The clinical assessments were based on the overall motor function of the patients. A mean TRS was defined as the mean of the three specialists’ assessments per time point. The measurements were repeated over several time points following a single levodopa/carbidopa morning dose (50% over normal to induce dyskinesias). Sensor measurements during rapid alternating movements of hands were processed with time series analysis methods to calculate spatiotemporal parameters designed to measure bradykinesia and dyskinesia. For each hand, 96 spatiotemporal parameters were calculated and their average scores were then used in a principal component analysis to reduce the dimensionality by retaining 6 principal components. These components were then used as predictors to support vector machines and to be mapped to the mean TRS ratings of the three specialists and to calculate the SBLRI. For this analysis, a 10-fold stratified cross-validation was performed. The SBLRI was strongly correlated to mean TRS with a Pearson correlation coefficient of 0.79 (CI: 0.74-0.83, p<0.001). The 95% confidence interval for the mean squared error of SBLRI on patients data was ± 1.62 with a mean value of 0.57 whereas on healthy controls data was ± 1 with a mean value of 0.27. The sensor-based spatiotemporal parameters had good internal consistency with a Cronbach’s Alpha coefficient of 0.87 and significantly differed between patients and healthy controls. The results demonstrated that the SBLRI had good clinimetric properties for measuring motor functions (Off and dyskinesia) in PD patients. The method could also distinguish hand rotation movements exhibited by patients from those exhibited by healthy controls. The SBLRI provides effect-time profiles, which could be useful during therapy individualization of advanced PD patients.

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  • 1918.
    Memedi, Mevludin
    et al.
    Örebro University, Örebro University School of Business.
    Tshering, Gaki
    Informatics, Business School, Örebro University, Örebro, Sweden.
    Fogelberg, Martin
    Informatics, Business School, Örebro University, Örebro, Sweden.
    Jusufi, Ilir
    Department of Computer Science and Media Technology, Linnaeus University, Växjö, Sweden.
    Kolkowska, Ella
    Örebro University, Örebro University School of Business.
    Klein, Gunnar O.
    Örebro University, Örebro University School of Business.
    An interface for IoT: feeding back health-related data to Parkinson's disease patients2018In: Journal of Sensor and Actuator Networks, E-ISSN 2224-2708, Vol. 7, no 1, article id 14Article in journal (Refereed)
    Abstract [en]

    This paper presents a user-centered design (UCD) process of an interface for Parkinson’s disease (PD) patients for helping them to better manage their symptoms. The interface is designed to visualize symptom and medication information, collected by an Internet of Things (IoT)-based system, which will consist of a smartphone, electronic dosing device, wrist sensor and a bed sensor. In our work, the focus is on measuring data related to some of the main health-related quality of life aspects such as motor function, sleep, medication compliance, meal intake timing in relation to medication intake, and physical exercise. A mock-up demonstrator for the interface was developed using UCD methodology in collaboration with PD patients. The research work was performed as an iterative design and evaluation process based on interviews and observations with 11 PD patients. Additional usability evaluations were conducted with three information visualization experts. Contributions include a list of requirements for the interface, results evaluating the performance of the patients when using the demonstrator during task-based evaluation sessions as well as opinions of the experts. The list of requirements included ability of the patients to track an ideal day, so they could repeat certain activities in the future as well as determine how the scores are related to each other. The patients found the visualizations as clear and easy to understand and could successfully perform the tasks. The evaluation with experts showed that the visualizations are in line with the current standards and guidelines for the intended group of users. In conclusion, the results from this work indicate that the proposed system can be considered as a tool for assisting patients in better management of the disease by giving them insights on their own aggregated symptom and medication information. However, the actual effects of providing such feedback to patients on their health-related quality of life should be investigated in a clinical trial.

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    An Interface for IoT: Feeding Back Health-Related Data to Parkinson’s Disease Patients
  • 1919.
    Memedi, Mevludin
    et al.
    Örebro University, School of Science and Technology. Department of Economy and Society, Computer Engineering, Dalarna University, Borlänge, Sweden.
    Westin, Jerker
    Department of Economy and Society, Computer Engineering, Dalarna University, Borlänge, Sweden.
    Nyholm, Dag
    Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Dougherty, Mark
    Department of Economy and Society, Computer Engineering, Dalarna University, Borlänge, Sweden.
    Groth, Torgny
    Department of Medical Sciences, Biomedical Informatics and Engineering, Uppsala University, Uppsala, Sweden.
    A web application for follow-up of results from a mobile device test battery for Parkinson's disease patients2011In: Computer Methods and Programs in Biomedicine, ISSN 0169-2607, E-ISSN 1872-7565, Vol. 104, no 2, p. 219-226Article in journal (Refereed)
    Abstract [en]

    This paper describes a web-based system for enabling remote monitoring of patients with Parkinson's disease (PD) and supporting clinicians in treating their patients. The system consists of a patient node for subjective and objective data collection based on a handheld computer, a service node for data storage and processing, and a web application for data presentation. Using statistical and machine learning methods, time series of raw data are summarized into scores for conceptual symptom dimensions and an “overall test score” providing a comprehensive profile of patient's health during a test period of about one week. The handheld unit was used quarterly or biannually by 65 patients with advanced PD for up to four years at nine clinics in Sweden. The IBM Computer System Usability Questionnaire was administered to assess nurses’ satisfaction with the web application. Results showed that a majority of the nurses were quite satisfied with the usability although a sizeable minority were not. Our findings support that this system can become an efficient tool to easily access relevant symptom information from the home environment of PD patients.

  • 1920.
    Mendoza Hallin, Karl
    Örebro University, School of Science and Technology.
    Measurements and Feature Detection in Scientific Visualization2022Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The work in this report focuses on atomic semi-classical magnetization dynamicsas implemented in the software package Cahmd, a classical atomisticHeisenberg-based magnetization dynamics toolbox by Danny Thonig et al. Theproject is about a state-of-the-art problem in theoretical condensed matterphysics. More precisely, the idea was about using modern 3D data visualizationbased on Vulkan and extend existing human-computer interaction aspectsfor detection of features and problem dependent properties. Such feature detectionwill be applied on the problem of atomistic magnetization dynamics.It will be applied to systems in thermalized states, but also systems hostingquasiparticle excitations.

    Download full text (pdf)
    fulltext
  • 1921.
    Menicatti, Roberto
    et al.
    University of Genova, Genova, Italy.
    Recchiuto, Carmine Tommaso
    University of Genova, Genova, Italy.
    Bruno, Barbara
    University of Genova, Genova, Italy.
    Zaccaria, Renato
    University of Genova, Genova, Italy.
    Khaliq, Ali Abdul
    Örebro University, School of Science and Technology.
    Köckemann, Uwe
    Örebro University, School of Science and Technology.
    Pecora, Federico
    Örebro University, School of Science and Technology.
    Saffiotti, Alessandro
    Örebro University, School of Science and Technology.
    Bui, Ha-Duong
    Japan Advanced Institute of Science and Technology, Japan .
    Chong, Nak Young
    Japan Advanced Institute of Science and Technology.
    Lim, Yuto
    Japan Advanced Institute of Science and Technology, Japan.
    Pham, Van Cu
    Japan Advanced Institute of Science and Technology, Japan.
    Tuyen, Nguyen Tan Viet
    Japan Advanced Institute of Science and Technology, Japan.
    Melo, Nicholas
    Chubu University, Japan.
    Lee, Jaeryoung
    Chubu University, Japan.
    Busy, Maxime
    Softbank Robotics Europe, Paris, France.
    Lagrue, Edouard
    Softbank Robotics Europe, Paris, France.
    Montanier, Jean–Marc
    Softbank Robotics Europe, Paris, France.
    Pandey, Amit Kumar
    Softbank Robotics Europe, Paris, France.
    Sgorbissa, Antonio
    University of Genova, Genova, Italy.
    Collaborative Development Within a Social Robotic, Multi-Disciplinary Effort: the CARESSES Case Study2018In: 2018 IEEE Workshop on Advanced Robotics and its Social Impacts (ARSO), IEEE, 2018, p. 117-124Conference paper (Refereed)
    Abstract [en]

    In many cases, complex multidisciplinary research projects may show a lack of coordinated development and integration, and a big effort is often required in the final phase of the projects in order to merge software developed by heterogeneous research groups. This is particularly true in advanced robotic projects: the objective here is to deliver a system that integrates all the hardware and software components, is capable of autonomous behaviour, and needs to be deployed in real-world scenarios toward providing an impact on future research and, ultimately, on society. On the other hand, in recent years there has been a growing interest for techniques related to software integration, but these have been mostly applied to the IT commercial domain.

    This paper presents the work performed in the context of the project CARESSES, a multidisciplinary research project focusing on socially assistive robotics that involves 9 partners from the EU and Japan. Given the complexity of the project, a huge importance has been placed on software integration, task planning and architecture definition since the first stages of the work: to this aim, some of the practices commonly used in the commercial domain for software integration, such as merging software from the early stage, have been applied. As a case study, the document describes the steps which have been followed in the first year of the project discussing strengths and weaknesses of this approach.

  • 1922.
    Mersie, Senay
    Örebro University, Örebro University School of Business.
    Mobile service readiness in Ethiopia: Technological and social perspective2011Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the last decade the growth of mobile technology and distribution of mobile phones is much faster as compared to the distribution and availability of personal computers. By the end of 2008, there were 246 million mobile subscriptions in Africa and some African countries are approaching 100% mobile population coverage. In Ethiopia currently there are no visible initiatives that can support the delivery of public service by utilizing the mobile technology. The overall aim of the research is to investigate the current technological and social readiness in Ethiopia to successfully implement mobile service. To achieve our aim we conduct a web survey along with an interview. From our results we come up with the conclusion that currently mobile phones are the best option available to provide public service, which can be accessed by more peoples in Ethiopia. Also Ethiopia is technologically and socially ready to implement mobile services.

  • 1923.
    Meyaki, Ahmed Hafiz Sadiq
    et al.
    Örebro University, Swedish Business School at Örebro University.
    Jakobov, Önay
    Örebro University, Swedish Business School at Örebro University.
    Public - Private Partnership in ICT for Development: The Ghanaian Experiment/Experience2008Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
  • 1924.
    Mielle, Malcolm
    Örebro University, School of Science and Technology.
    Helping robots help us: Using prior information for localization, navigation, and human-robot interaction2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Maps are often used to provide information and guide people. Emergency maps or floor plans are often displayed on walls and sketch maps can easily be drawn to give directions. However, robots typically assume that no knowledge of the environment is available before exploration even though making use of prior maps could enhance robotic mapping. For example, prior maps can be used to provide map data of places that the robot has not yet seen, to correct errors in robot maps, as well as to transfer information between map representations.

    I focus on two types of prior maps representing the walls of an indoor environment: layout maps and sketch maps. I study ways to relate information of sketch or layout maps with an equivalent metric map and study how to use layout maps to improve the robot’s mapping. Compared to metric maps such as sensor-built maps, layout and sketch maps can have local scale errors or miss elements of the environment, which makes matching and aligning such heterogeneous map types a hard problem.

    I aim to answer three research questions: how to interpret prior maps by finding meaningful features? How to find correspondences between the features of a prior map and a metric map representing the same environment? How to integrate prior maps in SLAM so that both the prior map and the map built by the robot are improved?

    The first contribution of this thesis is an algorithm that can find correspondences between regions of a hand-drawn sketch map and an equivalent metric map and achieves an overall accuracy that is within 10% of that of a human. The second contribution is a method that enables the integration of layout map data in SLAM and corrects errors both in the layout and the sensor map.

    These results provide ways to use prior maps with local scale errors and different levels of detail, whether they are close to metric maps, e.g. layout maps, or non-metric maps, e.g. sketch maps. The methods presented in this work were used in field tests with professional fire-fighters for search and rescue applications in low-visibility environments. A novel radar sensor was used to perform SLAM in smoke and, using a layout map as a prior map, users could indicate points of interest to the robot on the layout map, not only during and after exploration, but even before it took place.

    List of papers
    1. Using sketch-maps for robot navigation: interpretation and matching
    Open this publication in new window or tab >>Using sketch-maps for robot navigation: interpretation and matching
    2016 (English)In: 2016 IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR), New York: Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 252-257Conference paper, Published paper (Refereed)
    Abstract [en]

    We present a study on sketch-map interpretationand sketch to robot map matching, where maps have nonuniform scale, different shapes or can be incomplete. For humans, sketch-maps are an intuitive way to communicate navigation information, which makes it interesting to use sketch-maps forhuman robot interaction; e.g., in emergency scenarios.

    To interpret the sketch-map, we propose to use a Voronoi diagram that is obtained from the distance image on which a thinning parameter is used to remove spurious branches. The diagram is extracted as a graph and an efficient error-tolerant graph matching algorithm is used to find correspondences, while keeping time and memory complexity low.

    A comparison against common algorithms for graph extraction shows that our method leads to twice as many good matches. For simple maps, our method gives 95% good matches even for heavily distorted sketches, and for a more complex real-world map, up to 58%. This paper is a first step toward using unconstrained sketch-maps in robot navigation.

    Place, publisher, year, edition, pages
    New York: Institute of Electrical and Electronics Engineers (IEEE), 2016
    Keywords
    sketch, sketch-map, human robot interface, HRI, graph matching
    National Category
    Computer Sciences
    Research subject
    Computer Science
    Identifiers
    urn:nbn:se:oru:diva-53826 (URN)10.1109/SSRR.2016.7784307 (DOI)000391310800039 ()2-s2.0-85009754966 (Scopus ID)978-1-5090-4349-1 (ISBN)
    Conference
    14th IEEE International Symposium on Safety, Security and Rescue Robotics (SSRR 2016), EPFL, Lausanne, Switzerland, October 23-27, 2016
    Funder
    EU, Horizon 2020, ICT-23-2014 645101 SmokeBot
    Available from: 2016-12-09 Created: 2016-12-07 Last updated: 2019-10-02Bibliographically approved
    2. A method to segment maps from different modalities using free space layout MAORIS: map of ripples segmentation
    Open this publication in new window or tab >>A method to segment maps from different modalities using free space layout MAORIS: map of ripples segmentation
    2018 (English)Conference paper, Published paper (Refereed)
    Abstract [en]

    How to divide floor plans or navigation maps into semantic representations, such as rooms and corridors, is an important research question in fields such as human-robot interaction, place categorization, or semantic mapping. While most works focus on segmenting robot built maps, those are not the only types of map a robot, or its user, can use. We present a method for segmenting maps from different modalities, focusing on robot built maps and hand-drawn sketch maps, and show better results than state of the art for both types.

    Our method segments the map by doing a convolution between the distance image of the map and a circular kernel, and grouping pixels of the same value. Segmentation is done by detecting ripple-like patterns where pixel values vary quickly, and merging neighboring regions with similar values.

    We identify a flaw in the segmentation evaluation metric used in recent works and propose a metric based on Matthews correlation coefficient (MCC). We compare our results to ground-truth segmentations of maps from a publicly available dataset, on which we obtain a better MCC than the state of the art with 0.98 compared to 0.65 for a recent Voronoi-based segmentation method and 0.70 for the DuDe segmentation method.

    We also provide a dataset of sketches of an indoor environment, with two possible sets of ground truth segmentations, on which our method obtains an MCC of 0.56 against 0.28 for the Voronoi-based segmentation method and 0.30 for DuDe.

    Place, publisher, year, edition, pages
    IEEE Computer Society, 2018
    Keywords
    map segmentation, free space, layout
    National Category
    Robotics
    Research subject
    Computer Science
    Identifiers
    urn:nbn:se:oru:diva-68421 (URN)10.1109/ICRA.2018.8461128 (DOI)000446394503114 ()
    Conference
    IEEE International Conference on Robotics and Automation (ICRA 2018), Brisbane, Australia, May 21-25, 2018
    Funder
    EU, Horizon 2020, ICT-23-2014 645101 SmokeBotKnowledge Foundation, 20140220
    Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2019-10-10Bibliographically approved
    3. URSIM: Unique Regions for Sketch Map Interpretation and Matching
    Open this publication in new window or tab >>URSIM: Unique Regions for Sketch Map Interpretation and Matching
    2019 (English)In: Robotics, E-ISSN 2218-6581, Vol. 8, no 2, article id 43Article in journal (Refereed) Published
    Abstract [en]

    We present a method for matching sketch maps to a corresponding metric map, with the aim of later using the sketch as an intuitive interface for human-robot interactions. While sketch maps are not metrically accurate and many details, which are deemed unnecessary, are omitted, they represent the topology of the environment well and are typically accurate at key locations. Thus, for sketch map interpretation and matching, one cannot only rely on metric information. Our matching method first finds the most distinguishable, or unique, regions of two maps. The topology of the maps, the positions of the unique regions, and the size of all regions are used to build region descriptors. Finally, a sequential graph matching algorithm uses the region descriptors to find correspondences between regions of the sketch and metric maps. Our method obtained higher accuracy than both a state-of-the-art matching method for inaccurate map matching, and our previous work on the subject. The state of the art was unable to match sketch maps while our method performed only 10% worse than a human expert.

    Place, publisher, year, edition, pages
    MDPI, 2019
    Keywords
    Map matching, sketch, human-robot interaction, interface, graph matching, segmentation
    National Category
    Computer Vision and Robotics (Autonomous Systems)
    Identifiers
    urn:nbn:se:oru:diva-75741 (URN)10.3390/robotics8020043 (DOI)000475325600020 ()2-s2.0-85069975721 (Scopus ID)
    Funder
    Knowledge Foundation, 20140220
    Note

    Funding Agency:

    EU  ICT-26-2016 732737

    Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2020-02-06Bibliographically approved
    4. SLAM auto-complete: completing a robot map using an emergency map
    Open this publication in new window or tab >>SLAM auto-complete: completing a robot map using an emergency map
    2017 (English)In: 2017 IEEE International Symposium on Safety, Security and Rescue Robotics (SSRR), IEEE conference proceedings, 2017, p. 35-40, article id 8088137Conference paper, Published paper (Refereed)
    Abstract [en]

    In search and rescue missions, time is an important factor; fast navigation and quickly acquiring situation awareness might be matters of life and death. Hence, the use of robots in such scenarios has been restricted by the time needed to explore and build a map. One way to speed up exploration and mapping is to reason about unknown parts of the environment using prior information. While previous research on using external priors for robot mapping mainly focused on accurate maps or aerial images, such data are not always possible to get, especially indoor. We focus on emergency maps as priors for robot mapping since they are easy to get and already extensively used by firemen in rescue missions. However, those maps can be outdated, information might be missing, and the scales of rooms are typically not consistent.

    We have developed a formulation of graph-based SLAM that incorporates information from an emergency map. The graph-SLAM is optimized using a combination of robust kernels, fusing the emergency map and the robot map into one map, even when faced with scale inaccuracies and inexact start poses.

    We typically have more than 50% of wrong correspondences in the settings studied in this paper, and the method we propose correctly handles them. Experiments in an office environment show that we can handle up to 70% of wrong correspondences and still get the expected result. The robot can navigate and explore while taking into account places it has not yet seen. We demonstrate this in a test scenario and also show that the emergency map is enhanced by adding information not represented such as closed doors or new walls.

    Place, publisher, year, edition, pages
    IEEE conference proceedings, 2017
    Keywords
    SLAM, robotics, graph, graph SLAM, emergency map, rescue, exploration, auto complete, SLAM, robotics, graph, graph SLAM, plan de secours, sauvetage, exploration, auto complete
    National Category
    Computer Vision and Robotics (Autonomous Systems)
    Research subject
    Computer Science
    Identifiers
    urn:nbn:se:oru:diva-62057 (URN)10.1109/SSRR.2017.8088137 (DOI)000426991900007 ()2-s2.0-85040221684 (Scopus ID)978-1-5386-3923-8 (ISBN)978-1-5386-3924-5 (ISBN)
    Conference
    15th IEEE International Symposium on Safety, Security and Rescue Robotics (SSRR 2017), ShanghaiTech University, China, October 11-13, 2017
    Projects
    EU H2020 project SmokeBot (ICT- 23-2014 645101)
    Funder
    Knowledge Foundation, 20140220
    Note

    Funding Agency:

    EU  ICT-23-2014645101

    Available from: 2017-11-08 Created: 2017-11-08 Last updated: 2020-03-10Bibliographically approved
    5. The Auto-Complete Graph: Merging and Mutual Correction of Sensor and Prior Maps for SLAM
    Open this publication in new window or tab >>The Auto-Complete Graph: Merging and Mutual Correction of Sensor and Prior Maps for SLAM
    2019 (English)In: Robotics, E-ISSN 2218-6581, Vol. 8, no 2, article id 40Article in journal (Refereed) Published
    Abstract [en]

    Simultaneous Localization And Mapping (SLAM) usually assumes the robot starts without knowledge of the environment. While prior information, such as emergency maps or layout maps, is often available, integration is not trivial since such maps are often out of date and have uncertainty in local scale. Integration of prior map information is further complicated by sensor noise, drift in the measurements, and incorrect scan registrations in the sensor map. We present the Auto-Complete Graph (ACG), a graph-based SLAM method merging elements of sensor and prior maps into one consistent representation. After optimizing the ACG, the sensor map's errors are corrected thanks to the prior map, while the sensor map corrects the local scale inaccuracies in the prior map. We provide three datasets with associated prior maps: two recorded in campus environments, and one from a fireman training facility. Our method handled up to 40% of noise in odometry, was robust to varying levels of details between the prior and the sensor map, and could correct local scale errors of the prior. In field tests with ACG, users indicated points of interest directly on the prior before exploration. We did not record failures in reaching them.

    Place, publisher, year, edition, pages
    MDPI, 2019
    Keywords
    SLAM, prior map, emergency map, layout map, graph-based SLAM, navigation, search and rescue
    National Category
    Computer Vision and Robotics (Autonomous Systems)
    Identifiers
    urn:nbn:se:oru:diva-75742 (URN)10.3390/robotics8020040 (DOI)000475325600017 ()2-s2.0-85069926702 (Scopus ID)
    Funder
    Knowledge Foundation, 20140220
    Note

    Funding Agency:

    EU  ICT-26-2016 732737  ICT-23-2014 645101

    Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2020-02-06Bibliographically approved
    6. A comparative analysis of radar and lidar sensing for localization and mapping
    Open this publication in new window or tab >>A comparative analysis of radar and lidar sensing for localization and mapping
    2019 (English)In: 2019 European Conference on Mobile Robots (ECMR), IEEE, 2019Conference paper, Published paper (Refereed)
    Abstract [en]

    Lidars and cameras are the sensors most commonly used for Simultaneous Localization And Mapping (SLAM). However, they are not effective in certain scenarios, e.g. when fire and smoke are present in the environment. While radars are much less affected by such conditions, radar and lidar have rarely been compared in terms of the achievable SLAM accuracy. We present a principled comparison of the accuracy of a novel radar sensor against that of a Velodyne lidar, for localization and mapping.

    We evaluate the performance of both sensors by calculating the displacement in position and orientation relative to a ground-truth reference positioning system, over three experiments in an indoor lab environment. We use two different SLAM algorithms and found that the mean displacement in position when using the radar sensor was less than 0.037 m, compared to 0.011m for the lidar. We show that while producing slightly less accurate maps than a lidar, the radar can accurately perform SLAM and build a map of the environment, even including details such as corners and small walls.

    Place, publisher, year, edition, pages
    IEEE, 2019
    National Category
    Computer Vision and Robotics (Autonomous Systems)
    Identifiers
    urn:nbn:se:oru:diva-76976 (URN)10.1109/ECMR.2019.8870345 (DOI)000558081900002 ()2-s2.0-85074389854 (Scopus ID)978-1-7281-3605-9 (ISBN)978-1-7281-3606-6 (ISBN)
    Conference
    9th European Conference on Mobile Robots (ECMR 2019), Prague, Czech Republic, September 4-6, 2019
    Funder
    Knowledge Foundation, 20140220
    Note

    Funding Agency:

    EIT Raw Materials project FIREMII  18011

    Available from: 2019-10-02 Created: 2019-10-02 Last updated: 2020-09-16Bibliographically approved
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    Helping robots help us: Using prior information for localization, navigation, and human-robot interaction
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    Spikblad
  • 1925.
    Mielle, Malcolm
    et al.
    Örebro University, School of Science and Technology.
    Magnusson, Martin
    Örebro University, School of Science and Technology.
    Andreasson, Henrik
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    SLAM auto-complete: completing a robot map using an emergency map2017In: 2017 IEEE International Symposium on Safety, Security and Rescue Robotics (SSRR), IEEE conference proceedings, 2017, p. 35-40, article id 8088137Conference paper (Refereed)
    Abstract [en]

    In search and rescue missions, time is an important factor; fast navigation and quickly acquiring situation awareness might be matters of life and death. Hence, the use of robots in such scenarios has been restricted by the time needed to explore and build a map. One way to speed up exploration and mapping is to reason about unknown parts of the environment using prior information. While previous research on using external priors for robot mapping mainly focused on accurate maps or aerial images, such data are not always possible to get, especially indoor. We focus on emergency maps as priors for robot mapping since they are easy to get and already extensively used by firemen in rescue missions. However, those maps can be outdated, information might be missing, and the scales of rooms are typically not consistent.

    We have developed a formulation of graph-based SLAM that incorporates information from an emergency map. The graph-SLAM is optimized using a combination of robust kernels, fusing the emergency map and the robot map into one map, even when faced with scale inaccuracies and inexact start poses.

    We typically have more than 50% of wrong correspondences in the settings studied in this paper, and the method we propose correctly handles them. Experiments in an office environment show that we can handle up to 70% of wrong correspondences and still get the expected result. The robot can navigate and explore while taking into account places it has not yet seen. We demonstrate this in a test scenario and also show that the emergency map is enhanced by adding information not represented such as closed doors or new walls.

    Download full text (pdf)
    SLAM auto-complete: completing a robot map using an emergency map
  • 1926.
    Mielle, Malcolm
    et al.
    Örebro University, School of Science and Technology.
    Magnusson, Martin
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    A comparative analysis of radar and lidar sensing for localization and mapping2019In: 2019 European Conference on Mobile Robots (ECMR), IEEE, 2019Conference paper (Refereed)
    Abstract [en]

    Lidars and cameras are the sensors most commonly used for Simultaneous Localization And Mapping (SLAM). However, they are not effective in certain scenarios, e.g. when fire and smoke are present in the environment. While radars are much less affected by such conditions, radar and lidar have rarely been compared in terms of the achievable SLAM accuracy. We present a principled comparison of the accuracy of a novel radar sensor against that of a Velodyne lidar, for localization and mapping.

    We evaluate the performance of both sensors by calculating the displacement in position and orientation relative to a ground-truth reference positioning system, over three experiments in an indoor lab environment. We use two different SLAM algorithms and found that the mean displacement in position when using the radar sensor was less than 0.037 m, compared to 0.011m for the lidar. We show that while producing slightly less accurate maps than a lidar, the radar can accurately perform SLAM and build a map of the environment, even including details such as corners and small walls.

    Download full text (pdf)
    A comparative analysis of radar and lidar sensing for localization and mapping
  • 1927.
    Mielle, Malcolm
    et al.
    Örebro University, School of Science and Technology.
    Magnusson, Martin
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    The Auto-Complete Graph: Merging and Mutual Correction of Sensor and Prior Maps for SLAM2019In: Robotics, E-ISSN 2218-6581, Vol. 8, no 2, article id 40Article in journal (Refereed)
    Abstract [en]

    Simultaneous Localization And Mapping (SLAM) usually assumes the robot starts without knowledge of the environment. While prior information, such as emergency maps or layout maps, is often available, integration is not trivial since such maps are often out of date and have uncertainty in local scale. Integration of prior map information is further complicated by sensor noise, drift in the measurements, and incorrect scan registrations in the sensor map. We present the Auto-Complete Graph (ACG), a graph-based SLAM method merging elements of sensor and prior maps into one consistent representation. After optimizing the ACG, the sensor map's errors are corrected thanks to the prior map, while the sensor map corrects the local scale inaccuracies in the prior map. We provide three datasets with associated prior maps: two recorded in campus environments, and one from a fireman training facility. Our method handled up to 40% of noise in odometry, was robust to varying levels of details between the prior and the sensor map, and could correct local scale errors of the prior. In field tests with ACG, users indicated points of interest directly on the prior before exploration. We did not record failures in reaching them.

    Download full text (pdf)
    The Auto-Complete Graph: Merging and Mutual Correction of Sensor and Prior Maps for SLAM
    Download full text (txt)
    Publiceringsmedgivande
  • 1928.
    Mielle, Malcolm
    et al.
    Örebro University, School of Science and Technology.
    Magnusson, Martin
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    URSIM: Unique Regions for Sketch Map Interpretation and Matching2019In: Robotics, E-ISSN 2218-6581, Vol. 8, no 2, article id 43Article in journal (Refereed)
    Abstract [en]

    We present a method for matching sketch maps to a corresponding metric map, with the aim of later using the sketch as an intuitive interface for human-robot interactions. While sketch maps are not metrically accurate and many details, which are deemed unnecessary, are omitted, they represent the topology of the environment well and are typically accurate at key locations. Thus, for sketch map interpretation and matching, one cannot only rely on metric information. Our matching method first finds the most distinguishable, or unique, regions of two maps. The topology of the maps, the positions of the unique regions, and the size of all regions are used to build region descriptors. Finally, a sequential graph matching algorithm uses the region descriptors to find correspondences between regions of the sketch and metric maps. Our method obtained higher accuracy than both a state-of-the-art matching method for inaccurate map matching, and our previous work on the subject. The state of the art was unable to match sketch maps while our method performed only 10% worse than a human expert.

    Download full text (pdf)
    URSIM: Unique Regions for Sketch Map Interpretation and Matching
  • 1929.
    Mielle, Malcolm
    et al.
    Örebro University, School of Science and Technology.
    Magnusson, Martin
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Using sketch-maps for robot navigation: interpretation and matching2016In: 2016 IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR), New York: Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 252-257Conference paper (Refereed)
    Abstract [en]

    We present a study on sketch-map interpretationand sketch to robot map matching, where maps have nonuniform scale, different shapes or can be incomplete. For humans, sketch-maps are an intuitive way to communicate navigation information, which makes it interesting to use sketch-maps forhuman robot interaction; e.g., in emergency scenarios.

    To interpret the sketch-map, we propose to use a Voronoi diagram that is obtained from the distance image on which a thinning parameter is used to remove spurious branches. The diagram is extracted as a graph and an efficient error-tolerant graph matching algorithm is used to find correspondences, while keeping time and memory complexity low.

    A comparison against common algorithms for graph extraction shows that our method leads to twice as many good matches. For simple maps, our method gives 95% good matches even for heavily distorted sketches, and for a more complex real-world map, up to 58%. This paper is a first step toward using unconstrained sketch-maps in robot navigation.

  • 1930.
    Mikkelä, Julius
    Örebro University, Örebro University School of Business.
    Should I Cyborg? - A study into public opinion on Human Enhancement Technologies2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Download full text (pdf)
    fulltext
  • 1931.
    Milford, Michael
    et al.
    Australian Centre for Robotic Vision, Queensland University of Technology Australia, Brisbane, Australia .
    Shen, Chunhua
    Australian Centre for Robotic Vision, The University of Adelaide, Adelaide, Australia.
    Lowry, Stephanie
    Australian Centre for Robotic Vision, Queensland University of Technology Australia, Brisbane, Australia .
    Sünderhauf, Niko
    Australian Centre for Robotic Vision, Queensland University of Technology Australia, Brisbane, Australia .
    Shirazi, Sareh
    Australian Centre for Robotic Vision, Queensland University of Technology Australia, Brisbane, Australia .
    Lin, Guosheng
    Australian Centre for Robotic Vision, The University of Adelaide, Australia, Adelaide, Australia.
    Liu, Fayao
    Australian Centre for Robotic Vision, The University of Adelaide, Australia, Adelaide, Australia.
    Pepperell, Edward
    Australian Centre for Robotic Vision, Queensland University of Technology Australia, Brisbane, Australia .
    Cadena, Cesar
    Australian Centre for Robotic Vision, The University of Adelaide, Australia, Adelaide, Australia.
    Upcroft, Ben
    Australian Centre for Robotic Vision, Queensland University of Technology Australia, Brisbane, Australia .
    Reid, Ian
    Australian Centre for Robotic Vision, The University of Adelaide, Australia, Adelaide, Australia.
    Sequence Searching With Deep-Learnt Depth for Condition- and Viewpoint-Invariant Route-Based Place Recognition2015In: 2015 IEEE Conference on Computer Vision and Pattern Recognition Workshops, IEEE conference proceedings, 2015, p. 18-25Conference paper (Other academic)
    Abstract [en]

    Vision-based localization on robots and vehicles remains unsolved when extreme appearance change and viewpoint change are present simultaneously. The current state of the art approaches to this challenge either deal with only one of these two problems; for example FAB-MAP (viewpoint invariance) or SeqSLAM (appearance-invariance), or use extensive training within the test environment, an impractical requirement in many application scenarios. In this paper we significantly improve the viewpoint invariance of the SeqSLAM algorithm by using state-of-the-art deep learning techniques to generate synthetic viewpoints. Our approach is different to other deep learning approaches in that it does not rely on the ability of the CNN network to learn invariant features, but only to produce "good enough" depth images from day-time imagery only. We evaluate the system on a new multi-lane day-night car dataset specifically gathered to simultaneously test both appearance and viewpoint change. Results demonstrate that the use of synthetic viewpoints improves the maximum recall achieved at 100% precision by a factor of 2.2 and maximum recall by a factor of 2.7, enabling correct place recognition across multiple road lanes and significantly reducing the time between correct localizations.

  • 1932.
    Mitsioni, Ioanna
    et al.
    Division of Robotics, Perception and Learning (RPL), CAS, EECS, KTH Royal Institute of Technology, Stockholm, Sweden.
    Karayiannidis, Yiannis
    Division of Systems and Control, Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    Stork, Johannes Andreas
    Örebro University, School of Science and Technology.
    Kragic, Danica
    Division of Robotics, Perception and Learning (RPL), CAS, EECS, KTH Royal Institute of Technology, Stockholm, Sweden.
    Data-Driven Model Predictive Control for Food-CuttingManuscript (preprint) (Other academic)
    Abstract [en]

    Modelling of contact-rich tasks is challenging and cannot be entirely solved using classical control approaches due to the difficulty of constructing an analytic description of the contact dynamics. Additionally, in a manipulation task like food-cutting, purely learning-based methods such as Reinforcement Learning, require either a vast amount of data that is expensive to collect on a real robot, or a highly realistic simulation environment, which is currently not available. This paper presents a data-driven control approach that employs a recurrent neural network to model the dynamics for a Model Predictive Controller. We extend on previous work that was limited to torque-controlled robots by incorporating Force/Torque sensor measurements and formulate the control problem so that it can be applied to the more common velocity controlled robots. We evaluate the performance on objects used for training, as well as on unknown objects, by means of the cutting rates achieved and demonstrate that the method can efficiently treat different cases with only one dynamic model. Finally we investigate the behavior of the system during force-critical instances of cutting and illustrate its adaptive behavior in difficult cases.

  • 1933.
    Mitsioni, Ioanna
    et al.
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Karayiannidis, Yiannis
    Chalmers University of Technology , Gothenburg, Sweden; KTH Royal Institute of Technology, Stockholm, Sweden.
    Stork, Johannes Andreas
    Örebro University, School of Science and Technology.
    Kragic, Danica
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Data-Driven Model Predictive Control for the Contact-Rich Task of Food Cutting2019In: IEEE-RAS International Conference on Humanoid Robots, IEEE Computer Society, 2019, p. 244-250, article id 9035011Conference paper (Refereed)
    Abstract [en]

    Modelling of contact-rich tasks is challenging and cannot be entirely solved using classical control approaches due to the difficulty of constructing an analytic description of the contact dynamics. Additionally, in a manipulation task like food-cutting, purely learning-based methods such as Reinforcement Learning, require either a vast amount of data that is expensive to collect on a real robot, or a highly realistic simulation environment, which is currently not available. This paper presents a data-driven control approach that employs a recurrent neural network to model the dynamics for a Model Predictive Controller. We build upon earlier work limited to torque-controlled robots and redefine it for velocity controlled ones. We incorporate force/torque sensor measurements, reformulate and further extend the control problem formulation. We evaluate the performance on objects used for training, as well as on unknown objects, by means of the cutting rates achieved and demonstrate that the method can efficiently treat different cases with only one dynamic model. Finally we investigate the behavior of the system during force-critical instances of cutting and illustrate its adaptive behavior in difficult cases.

  • 1934.
    Mizyed, Maya
    Örebro University, Örebro University School of Business.
    Agilt RUP/Plandrivna agila metoder: Hur arbetar företagen?2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 1935.
    Mohajerin, Nima
    Örebro University, School of Science and Technology.
    Identification and Predictive Control Using RecurrentNeural Networks2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this thesis, a special class of Recurrent Neural Networks (RNN) is employed

    for system identification and predictive control of time dependent systems.

    Fundamental architectures and learning algorithms of RNNs are studied

    upon which a generalized architecture over a class of state-space represented

    networks is proposed and formulated. Levenberg-Marquardt (LM) learning

    algorithm is derived for this architecture and a number of enhancements are

    introduced. Furthermore, using this recurrent neural network as a system identifier,

    a Model Predictive Controller (MPC) is established which solves the optimization

    problem using an iterative approach based on the LM algorithm.

    Simulation results show that the new architecture accompanied by LM learning

    algorithm outperforms some of existing methods. The third approach which

    utilizes the proposed method in on-line system identification enhances the identification/

    control process even more.

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  • 1936.
    Mohamed, Zozk
    Örebro University, School of Science and Technology.
    Analys av metoder för lokal rörelseplanering2021Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In recent years, we have been able to automate various processes and tasks with the help of robots that use motion planning. Today, there are very few strategies for local motion planning when compared to global motion planning. The purpose of this project has been to analyze three strategies for local motion planning, these have been Dynamic Window Approach (DWA), Elastic Band (Eband) and Timed Elastic Band (TEB).In the project, strengths, weaknesses, behaviours and opportunities for improvement for each strategy have been studied in more detail by performing various simulated tests. The tests measure time to reach the goal, the number of collisions and the number of succeeding attempts. During the project, a virtual omni-directional robot from ABB was used to perform the tests. The tests were performed in as fair a way as possible, where all strategies got the same number of attempts and had the same information about the robot's limitations.The results show that TEB is the fastest strategy, followed by DWA and last Eband that was the slowest strategy. TEB was also the strategy that performed best in dynamic obstacles, however, it was also the strategy that collided most of the tests, while Eband collided the least.

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    fulltext
  • 1937.
    Mojtahedzadeh, Rasoul
    Örebro University, School of Science and Technology.
    Safe Robotic Manipulation to Extract Objects from Piles: From 3D Perception to Object Selection2016Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis is concerned with the task of autonomous selection of objects to remove (unload) them from a pile in robotic manipulation systems. Applications such as the automation of logistics processes and service robots require an ability to autonomously manipulate objects in the environment. A collapse of a pile of objects due to an inappropriate choice of the object to be removed from the pile cannot be afforded for an autonomous robotic manipulation system. This dissertation presents an indepth analysis of the problem and proposes methods and algorithms to empower robotic manipulation systems to select a safe object from a pile elaborately and autonomously.

    The contributions presented in this thesis are three-fold. First, a set of algorithms is proposed for extracting a minimal set of high level symbolic relations, namely, gravitational act and support relations, of physical interactions between objects composing a pile. The symbolic relations, extracted by a geometrical reasoning method and a static equilibrium analysis can be readily used by AI paradigms to analyze the stability of a pile and reason about the safest set of objects to be removed. Considering the problem of undetected objects and the uncertainty in the estimated poses as they exist in realistic perception systems, a probabilistic approach is proposed to extract the support relations and to make a probabilistic decision about the set of safest objects using notions from machine learning and decision theory. Second, an efficient search based algorithm is proposed in an internal representation to automatically resolve the inter-penetrations between the shapes of objects due to errors in the poses estimated by an existing object detection module. Refining the poses by resolving the inter-penetrations results in a geometrically consistent model of the environment, and was found to reduce the overall pose error of the objects. This dissertation presents the concept of minimum translation search for object pose refinement and discusses a discrete search paradigm based on the concept of depth of penetration between two polyhedrons. Third, an application centric evaluation of ranging sensors for selecting a set of appropriate sensors for the task of object detection in the design process of a real-world robotics manipulation system is presented. The performance of the proposed algorithms are tested on data sets generated in simulation and from real-world scenarios.

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    Safe Robotic Manipulation to Extract Objects from Piles
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  • 1938.
    Mojtahedzadeh, Rasoul
    et al.
    Örebro University, School of Science and Technology.
    Bouguerra, Abdelbaki
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Automatic relational scene representation for safe robotic manipulation tasks2013Conference paper (Refereed)
    Abstract [en]

    In this paper, we propose a new approach forautomatically building symbolic relational descriptions of staticconfigurations of objects to be manipulated by a robotic system.The main goal of our work is to provide advanced cognitiveabilities for such robotic systems to make them more aware ofthe outcome of their actions. We describe how such symbolicrelations are automatically extracted for configurations ofbox-shaped objects using notions from geometry and staticequilibrium in classical mechanics. We also present extensivesimulation results as well as some real-world experiments aimedat verifying the output of the proposed approach.

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    Mojtahedzadeh_etal_2013-IROS-Automatic_Relational_Scene_Representation_for_Safe_Robotic_Manipulation_Tasks.pdf
  • 1939.
    Mojtahedzadeh, Rasoul
    et al.
    Örebro University, School of Science and Technology.
    Bouguerra, Abdelbaki
    Örebro University, School of Science and Technology.
    Schaffernicht, Erik
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Probabilistic Relational Scene Representation and Decision Making Under Incomplete Information for Robotic Manipulation Tasks2014In: Robotics and Automation (ICRA), 2014 IEEE International Conference on, IEEE Robotics and Automation Society, 2014, p. 5685-5690Conference paper (Refereed)
    Abstract [en]

    In this paper, we propose an approach for robotic manipulation systems to autonomously reason about their environments under incomplete information. The target application is to automate the task of unloading the content of shipping containers. Our goal is to capture possible support relations between objects in partially known static configurations. We employ support vector machines (SVM) to estimate the probability of a support relation between pairs of detected objects using features extracted from their geometrical properties and 3D sampled points of the scene. The set of probabilistic support relations is then used for reasoning about optimally selecting an object to be unloaded first. The proposed approach has been extensively tested and verified on data sets generated in simulation and from real world configurations.

  • 1940.
    Mojtahedzadeh, Rasoul
    et al.
    Örebro University, School of Science and Technology.
    Bouguerra, Abdelbaki
    Örebro University, School of Science and Technology.
    Schaffernicht, Erik
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J
    Örebro University, School of Science and Technology.
    Support relation analysis and decision making for safe robotic manipulation tasks2015In: Robotics and Autonomous Systems, ISSN 0921-8890, E-ISSN 1872-793X, Vol. 71, no SI, p. 99-117Article in journal (Refereed)
    Abstract [en]

    In this article, we describe an approach to address the issue of automatically building and using high-level symbolic representations that capture physical interactions between objects in static configurations. Our work targets robotic manipulation systems where objects need to be safely removed from piles that come in random configurations. We assume that a 3D visual perception module exists so that objects in the piles can be completely or partially detected. Depending on the outcome of the perception, we divide the issue into two sub-issues: 1) all objects in the configuration are detected; 2) only a subset of objects are correctly detected. For the first case, we use notions from geometry and static equilibrium in classical mechanics to automatically analyze and extract act and support relations between pairs of objects. For the second case, we use machine learning techniques to estimate the probability of objects supporting each other. Having the support relations extracted, a decision making process is used to identify which object to remove from the configuration so that an expected minimum cost is optimized. The proposed methods have been extensively tested and validated on data sets generated in simulation and from real world configurations for the scenario of unloading goods from shipping containers.

  • 1941.
    Mojtahedzadeh, Rasoul
    et al.
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    A principle of minimum translation search approach for object pose refinement2015In: 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) / [ed] IEEE, IEEE Press, 2015, p. 2897-2903Conference paper (Refereed)
    Abstract [en]

    The state-of-the-art object pose estimation approaches represent the set of detected poses together with corresponding uncertainty. The inaccurate noisy poses may result in a configuration of overlapping objects especially in cluttered environments. Under a rigid body assumption the inter-penetrations between pairs of objects are geometrically inconsistent. In this paper, we propose the principle of minimum translation search, PROMTS, to find an inter-penetration-free configuration of the initially detected objects. The target application is to automate the task of unloading shipping containers, where a geometrically consistent configuration of objects is required for high level reasoning and manipulation. We find that the proposed approach to resolve geometrical inconsistencies improves the overall pose estimation accuracy. We examine the utility of two selected search methods: A-star and Depth-Limited search. The performance of the search algorithms are tested on data sets generated in simulation and from real-world scenarios. The results show overall improvement of the estimated poses and suggest that depth-limited search presents the best overall performance.

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  • 1942.
    Mojtahedzadeh, Rasoul
    et al.
    Örebro University, School of Science and Technology.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Application Based 3D Sensor Evaluation: A Case Study in 3D Object Pose Estimation for Automated Unloading of Containers2013In: Proceedings of the European Conference on Mobile Robots (ECMR), IEEE conference proceedings, 2013, p. 313-318Conference paper (Other academic)
    Abstract [en]

    A fundamental task in the design process of a complex system that requires 3D visual perception is the choice of suitable 3D range sensors. Identifying the utility of 3D range sensors in an industrial application solely based on an evaluation of their distance accuracy and the noise level may lead to an inappropriate selection. To assess the actual effect on the performance of the system as a whole requires a more involved analysis. In this paper, we examine the problem of selecting a set of 3D range sensors when designing autonomous systems for specific industrial applications in a holistic manner. As an instance of this problem we present a case study with an experimental evaluation of the utility of four 3D range sensors for object pose estimation in the process of automation of unloading containers.

  • 1943.
    Moldovan, Bogdan
    et al.
    Department of Computer Science, Katholieke Universiteit Leuven, Leuven, Belgium.
    De Raedt, Luc
    Department of Computer Science, Katholieke Universiteit Leuven, Leuven, Belgium.
    Learning relational affordance models for two-arm robots2014In: 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE Press, 2014, p. 2916-2922Conference paper (Refereed)
    Abstract [en]

    Affordances are used in robotics to model action opportunities of a robotic manipulator on an object in the environment. Previous work has shown how statistical relational learning can be used in a discrete setting to extend affordances to model relations and interactions between multiple objects being manipulated by a robotic arm and deal with environment uncertainty. In this paper, we first extend this concept of relational affordances to a continuous setting and then to a two-arm robot. A relational affordance model can first be learnt for one arm through a behavioural babbling stage, and then with the use of statistical relational learning, after constructing a symmetrical model for the other arm, two-arm manipulation actions can be modelled, where the arms can act sequentially or simultaneously. The model is evaluated in a two-arm action recognition task in a shelf object manipulation setting.

  • 1944.
    Moldovan, Bogdan
    et al.
    Department of Computer Science, Katholieke Universiteit, Leuven, Belgium.
    De Raedt, Luc
    Department of Computer Science, Katholieke Universiteit, Leuven, Belgium.
    Occluded object search by relational affordances2014In: 2014 IEEE International Conference on Robotics & Automation (ICRA), IEEE, 2014, p. 169-174Conference paper (Refereed)
    Abstract [en]

    Searching for objects in occluded spaces is one of the problems robots need to solve when tackling mobile manipulation tasks. Most approaches focus only on searching for a specific object. In this paper, we use the concept of relational affordances to improve occluded object search performance. Affordances define action possibilities on an object in the environment and play a role in basic cognitive capabilities. Relational affordances extend this concept by modelling relations between multiple objects. By learning and using a relational affordance model we can search for any of the multiple objects that afford a given action, each object type having a probability distribution over possible sizes and shapes, and where spatial relations between objects such as co-occurrence and stacking are modelled. The experimental results show the viability of the relational affordance models for occluded object search.

  • 1945.
    Moldovan, Bogdan
    et al.
    Department of Computer Science, Katholieke Universiteit Leuven, Leuven, Belgium.
    Thon, Ingo
    Department of Computer Science, Katholieke Universiteit Leuven, Leuven, Belgium.
    Davis, Jesse
    Department of Computer Science, Katholieke Universiteit Leuven, Leuven, Belgium.
    De Raedt, Luc
    Department of Computer Science, Katholieke Universiteit Leuven, Leuven, Belgium.
    Estimation of Conditional Probabilities in Probabilistic Programming Languages2013In: Symbolic and Quantitative Approaches to Reasoning with Uncertainty: 12th European Conference, ECSQARU 2013, Utrecht, The Netherlands, July 8-10, 2013. Proceedings / [ed] van der Gaag, Linda C., Springer, 2013, Vol. 7958, p. 436-448Conference paper (Refereed)
    Abstract [en]

    Probabilistic logic programming languages are powerful formalisms that can model complex problems where it is necessary to represent both structure and uncertainty. Using exact inference methods to compute conditional probabilities in these languages is often intractable so approximate inference techniques are necessary. This paper proposes a Markov Chain Monte Carlo algorithm for estimating conditional probabilities based on sampling from an AND/OR tree for ProbLog, a general-purpose probabilistic logic programming language. We propose a parameterizable proposal distribution that generates the next sample in the Markov chain by probabilistically traversing the AND/OR tree from its root, which holds the evidence, to the leaves. An empirical evaluation on several different applications illustrates the advantages of our algorithm.

  • 1946.
    Moldovan, Bogdan
    et al.
    Department of Computer Science, Katholieke Universiteit Leuven, Belgium.
    van Otterlo, Martijn
    Department of Computer Science, Katholieke Universiteit Leuven, Belgium.
    De Raedt, Luc
    Department of Computer Science, Katholieke Universiteit Leuven, Belgium.
    Moreno, Plinio
    Electrical & Computer Engineering, Instituto Superior T ́ecnico, Portugal.
    Santos-Victor, José
    Electrical & Computer Engineering, Instituto Superior T ́ecnico, Portugal.
    Statistical Relational Learning of Object Affordances for Robotic Manipulation2014In: Latest Advances in Inductive Logic Programming, London: Imperial College Press, 2014, p. 95-103Chapter in book (Refereed)
    Abstract [en]

    We present initial results of an application of statistical relational learning using ProbLog to a robotic manipulation task modeled using affordances. Affordances encompass the action possibilities on an object, so previous works have presented models for just one object. However, in scenarios where there are multiple objects that interact, it is very useful to consider the advantages of the statistical relational learning.

  • 1947.
    Molina, Sergi
    et al.
    University of Lincoln, Lincoln, U.K.
    Mannucci, Anna
    Robert Bosch GmbH, Renningen, Germany.
    Magnusson, Martin
    Örebro University, School of Science and Technology.
    Adolfsson, Daniel
    Örebro University, School of Science and Technology.
    Andreasson, Henrik
    Örebro University, School of Science and Technology.
    Hamad, Mazin
    Technical University of Munich, Munich, Germany.
    Abdolshah, Saeed
    Technical University of Munich, Munich, Germany.
    Chadalavada, Ravi Teja
    Örebro University, School of Science and Technology.
    Palmieri, Luigi
    Robert Bosch GmbH, Renningen, Germany.
    Linder, Timm
    Robert Bosch GmbH, Renningen, Germany.
    Swaminathan, Chittaranjan Srinivas
    Örebro University, School of Science and Technology.
    Kucner, Tomasz Piotr
    Aalto University, Aalto, Finland.
    Hanheide, Marc
    University of Lincoln, Lincoln, U.K..
    Fernandez-Carmona, Manuel
    University of Lincoln, Lincoln, U.K..
    Cielniak, Grzegorz
    University of Lincoln, Lincoln, U.K..
    Duckett, Tom
    University of Lincoln, Lincoln, U.K..
    Pecora, Federico
    Örebro University, School of Science and Technology.
    Bokesand, Simon
    Kollmorgen Automation AB, Mölndal, Sweden.
    Arras, Kai O.
    Robert Bosch GmbH, Renningen, Germany.
    Haddadin, Sami
    Technical University of Munich, Munich, Germany.
    Lilienthal, Achim J
    Örebro University, School of Science and Technology.
    The ILIAD Safety Stack: Human-Aware Infrastructure-Free Navigation of Industrial Mobile Robots2023In: IEEE robotics & automation magazine, ISSN 1070-9932, E-ISSN 1558-223XArticle in journal (Refereed)
    Abstract [en]

    Current intralogistics services require keeping up with e-commerce demands, reducing delivery times and waste, and increasing overall flexibility. As a consequence, the use of automated guided vehicles (AGVs) and, more recently, autonomous mobile robots (AMRs) for logistics operations is steadily increasing.

  • 1948.
    Molka-Danielsen, Judith
    et al.
    Molde University, Molde, Norway.
    Deutschmann, MatsMid Sweden University, Sundsvall, Sweden.
    Learning and teaching in the virtual world of second life2009Collection (editor) (Refereed)
    Abstract [en]

    The book disseminates the experiences and lessons learned in various educational projects in Second Life.

  • 1949.
    Moll, Jonas
    et al.
    Department of Information Technology, Uppsala University, Uppsala, Sweden.
    Frid, Emma
    2Department of Media Technology and Interaction Design, KTH Royal Institute of Technology, Stockholm, Sweden.
    Using eye-tracking to study the effect of haptic feedback on visual focus during collaborative object managing in a multimodal virtual interface2017In: Proceedings of the 13th SweCog conference, Högskolan i Skövde , 2017, p. 49-51Conference paper (Refereed)
    Download full text (pdf)
    Using Eye-Tracking to Study the Effect of Haptic Feedback on Visual Focus During Collaborative Object Managing in a Multimodal Virtual Interface
  • 1950.
    Moll, Jonas
    et al.
    Department of Information Technology, Uppsala University, Uppsala, Sweden.
    Sallnäs Pysander, Eva-Lotta
    Department of Media Technology and Interaction Design, KTH Royal Institute of Technology, Stockholm, Sweden.
    Haptic communicative functions and their effects on communication in collaborative multimodal virtual environments2017In: Proceedings 13th SweCog Conference, Högskolan i Skövde , 2017, p. 63-64Conference paper (Refereed)
    Download full text (pdf)
    Haptic communicative functions and their effects on communication in collaborative multimodal virtual environments
36373839404142 1901 - 1950 of 2817
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