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  • 1.
    Albinsson, John
    et al.
    Lund Univ, Dept Biomed Engn, S-22100 Lund, Sweden..
    Brorsson, Sofia
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Rydén Ahlgren, Åsa
    Lund Univ, Dept Clin Sci, Clin Physiol & Nucl Med Unit, Malmo, Sweden..
    Cinthio, Magnus
    Lund Univ, Dept Biomed Engn, S-22100 Lund, Sweden..
    Improved tracking performance of lagrangian block-matching methodologies using block expansion in the time domain: In silico, phantom and invivo evaluations2014In: Ultrasound in Medicine and Biology, ISSN 0301-5629, E-ISSN 1879-291X, Vol. 40, no 10, p. 2508-2520Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to evaluate tracking performance when an extra reference block is added to a basic block-matching method, where the two reference blocks originate from two consecutive ultrasound frames. The use of an extra reference block was evaluated for two putative benefits: (i) an increase in tracking performance while maintaining the size of the reference blocks, evaluated using in silico and phantom cine loops; (ii) a reduction in the size of the reference blocks while maintaining the tracking performance, evaluated using in vivo cine loops of the common carotid artery where the longitudinal movement of the wall was estimated. The results indicated that tracking accuracy improved (mean - 48%, p<0.005 [in silico]; mean - 43%, p<0.01 [phantom]), and there was a reduction in size of the reference blocks while maintaining tracking performance (mean - 19%, p<0.01 [in vivo]). This novel method will facilitate further exploration of the longitudinal movement of the arterial wall. (C) 2014 World Federation for Ultrasound in Medicine & Biology.

  • 2.
    Alonso-Fernandez, Fernando
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Bigun, Josef
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Englund, Cristofer
    RISE Viktoria, Gothenburg, Sweden.
    Expression Recognition Using the Periocular Region: A Feasibility Study2018In: 2018 14th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS) / [ed] Gabriella Sanniti di Baja, Luigi Gallo, Kokou Yetongnon, Albert Dipanda, Modesto Castrillón-Santana & Richard Chbeir, Los Alamitos: IEEE Computer Society, 2018, p. 536-541Conference paper (Refereed)
    Abstract [en]

    This paper investigates the feasibility of using the periocular region for expression recognition. Most works have tried to solve this by analyzing the whole face. Periocular is the facial region in the immediate vicinity of the eye. It has the advantage of being available over a wide range of distances and under partial face occlusion, thus making it suitable for unconstrained or uncooperative scenarios. We evaluate five different image descriptors on a dataset of 1,574 images from 118 subjects. The experimental results show an average/overall accuracy of 67.0%/78.0% by fusion of several descriptors. While this accuracy is still behind that attained with full-face methods, it is noteworthy to mention that our initial approach employs only one frame to predict the expression, in contraposition to state of the art, exploiting several order more data comprising spatial-temporal data which is often not available.

  • 3.
    Alonso-Fernandez, Fernando
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Farrugia, Reuben
    University of Malta, Msida, Malta.
    Bigun, Josef
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Very Low-Resolution Iris Recognition Via Eigen-Patch Super-Resolution and Matcher Fusion2016In: 2016 IEEE 8th International Conference on Biometrics Theory, Applications and Systems (BTAS), Piscataway: IEEE, 2016, article id 7791208Conference paper (Refereed)
    Abstract [en]

    Current research in iris recognition is moving towards enabling more relaxed acquisition conditions. This has effects on the quality of acquired images, with low resolution being a predominant issue. Here, we evaluate a super-resolution algorithm used to reconstruct iris images based on Eigen-transformation of local image patches. Each patch is reconstructed separately, allowing better quality of enhanced images by preserving local information. Contrast enhancement is used to improve the reconstruction quality, while matcher fusion has been adopted to improve iris recognition performance. We validate the system using a database of 1,872 near-infrared iris images. The presented approach is superior to bilinear or bicubic interpolation, especially at lower resolutions, and the fusion of the two systems pushes the EER to below 5% for down-sampling factors up to a image size of only 13×13.

  • 4.
    Andersson, Evelina
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    The 2-dimensional biomechanical modeling of the loads on the spine (L5-L1) during a “Back Walkover” maneuver in gymnastics2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Injuries in the female gymnast are common and it is important to understand the biomechanical factors responsible for injury. The Back Walkover maneuver requires one of the greatest amounts of lumbar hyperextension compared to other common gymnastic maneuvers. During the Back Walkover large lateral and vertical impact forces follows on the spine. The spine and muscles around the spine have to absorb generally large forces; therefore the loads on the back and certainly on the lower back are of significant interest. Additionally, it takes a lot of strength and a vast range of motion to perform gymnastic maneuvers such as The Back Walkover. It is of interest to study mechanical loads on a female gymnast since they show higher occurrences of stress-related pathologies of the lumbar spine.

    Therefore the purpose of this project was to examine the loads on the spine during the gymnastic maneuver Back Walkover. Tests on a single female gymnast were made at the sports engineering lab at the University of Adelaide in Australia. Using the 3D-camera system; Optitrack Motion Capture System and Kistler Force Plate, positional data for two dimensions, X-direction (anterior-posterior) and Z-direction (vertical), and ground force were received. Data received were progressed into a graph, diagrams and biomechanical calculations where forces for the vertebrae L1 were calculated in vertical and horizontal direction. The received forces were compared to vertical and horizontal forces in L1 during standing position. Together with developed videos this assisted to model the loads of the spine (L1) during the gymnastic maneuver the “Back Walkover”. The study has led to a deeper knowledge for the community about the risks for female gymnasts and has widened the experience of the project participant, as the project aimed. 

  • 5.
    Andersson, Matilda
    Halmstad University, School of Business, Engineering and Science.
    Analysis of Changes in Running Technique Between a Shod and Barefoot Running Condition.2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background: Lately, barefoot running has become popular and there is a debate on the pros and cons of barefoot running with regards to running injuries. Many factors are causing injuries and one of the factors discussed is the fact that we run in shoes. When we run in shoes the biomechanics of the running technique may and therefore be a possible cause to injury. Aim: The aim of the study was to assess how the foot strike pattern, angle of the knee and ankle joint at time of initial contact, as well as the step length changes between a shod and barefoot running condition in habitually shod runners when running in a pace equivalent to their running pace over ten kilometers. Method: Twenty-seven healthy runners (18 male, 9 female) were included in the study. The study took place at the fitness center of Halmstad University. Subjects ran on a treadmill, in an individual pace equivalent to their running pace over ten km, both in a shod and barefoot running condition. Two-dimensional analysis of the sagittal plane kinematics of the knee joint, ankle joint and foot position to horizontal, foot strike pattern and step length was done. Participants ran for ten minutes with shoes and for five minutes barefoot. Running technique was videotaped using an Iphone 6 camera and landmarks were marked with white tape to ease the analysis. Results: Changes in foot strike pattern was observed. When running barefoot 63% of the subjects adopted a non-heel strike pattern compared to 18.5% when shod (p=0.001). Knee flexion was increased at IC for the barefoot condition, with 164°±6 relative knee angle compared to 167°±6 when shod (p=0.001). Ankle angle at IC did not show a statistical significant difference between conditions (p=0.657). When barefoot the angle was 117°±8 compared to 115°±8 when shod. Foot angle to horizontal showed a flatter foot placement at IC with a less dorsiflexed foot for the barefoot condition (-4°±8) compared to shod (-12°±8), (p=0.001). Step length was decreased for the barefoot condition (0.82m ±0.15)   compared to shod (0.85m ±0.13), (p=0.008). Conclusion: Results are consistent with previous findings that barefoot running in some cases change the running technique with a flatter foot placement, an increased knee flexion at IC and a decreased step length. However, caution must be taken when habitually shod runners transition to barefoot running in regards to the biomechanical changes that may occur. To benefit from barefoot running a non-heel strike pattern is required. Further, the running technique may be the more important factor, regardless of wearing shoes or not.

  • 6.
    Ashfaq, Awais
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research. KTH Royal Institute of Technology, Stockholm, Sweden.
    Adler, Jonas
    KTH Royal Institute of Technology, Stockholm, Sweden & Elekta Instrument AB, Stockholm, Sweden.
    A modified fuzzy C means algorithm for shading correction in craniofacial CBCT images2017In: CMBEBIH 2017: Proceedings of the International Conference on Medical and Biological Engineering 2017 / [ed] Almir Badnjevic, Singapore: Springer, 2017, Vol. 62, p. 531-538Conference paper (Refereed)
    Abstract [en]

    CBCT images suffer from acute shading artifacts primarily due to scatter. Numerous image-domain correction algorithms have been proposed in the literature that use patient-specific planning CT images to estimate shading contributions in CBCT images. However, in the context of radiosurgery applications such as gamma knife, planning images are often acquired through MRI which impedes the use of polynomial fitting approaches for shading correction. We present a new shading correction approach that is independent of planning CT images. Our algorithm is based on the assumption that true CBCT images follow a uniform volumetric intensity distribution per material, and scatter perturbs this uniform texture by contributing cupping and shading artifacts in the image domain. The framework is a combination of fuzzy C-means coupled with a neighborhood regularization term and Otsu’s method. Experimental results on artificially simulated craniofacial CBCT images are provided to demonstrate the effectiveness of our algorithm. Spatial non-uniformity is reduced from 16% to 7% in soft tissue and from 44% to 8% in bone regions. With shading-correction, thresholding based segmentation accuracy for bone pixels is improved from 85% to 91% when compared to thresholding without shading-correction. The proposed algorithm is thus practical and qualifies as a plug and play extension into any CBCT reconstruction software for shading correction. © Springer Nature Singapore Pte Ltd. 2017.

  • 7.
    Ashfaq, Awais
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research. Halland Hospital, Region Halland, Halmstad, Sweden.
    Nowaczyk, Sławomir
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Machine learning in healthcare - a system’s perspective2019In: Proceedings of the ACM SIGKDD Workshop on Epidemiology meets Data Mining and Knowledge Discovery (epiDAMIK) / [ed] B. Aditya Prakash, Anil Vullikanti, Shweta Bansal, Adam Sadelik, Arlington, 2019, p. 14-17Conference paper (Refereed)
    Abstract [en]

    A consequence of the fragmented and siloed healthcare landscape is that patient care (and data) is split along multitude of different facilities and computer systems and enabling interoperability between these systems is hard. The lack interoperability not only hinders continuity of care and burdens providers, but also hinders effective application of Machine Learning (ML) algorithms. Thus, most current ML algorithms, designed to understand patient care and facilitate clinical decision-support, are trained on limited datasets. This approach is analogous to the Newtonian paradigm of Reductionism in which a system is broken down into elementary components and a description of the whole is formed by understanding those components individually. A key limitation of the reductionist approach is that it ignores the component-component interactions and dynamics within the system which are often of prime significance in understanding the overall behaviour of complex adaptive systems (CAS). Healthcare is a CAS.

    Though the application of ML on health data have shown incremental improvements for clinical decision support, ML has a much a broader potential to restructure care delivery as a whole and maximize care value. However, this ML potential remains largely untapped: primarily due to functional limitations of Electronic Health Records (EHR) and the inability to see the healthcare system as a whole. This viewpoint (i) articulates the healthcare as a complex system which has a biological and an organizational perspective, (ii) motivates with examples, the need of a system's approach when addressing healthcare challenges via ML and, (iii) emphasizes to unleash EHR functionality - while duly respecting all ethical and legal concerns - to reap full benefits of ML.

  • 8.
    Bäckman, Sandra
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Produktutvecklingsprojekt: En applikation till användandet av oxygenbehandling i hemmet.2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    According to statistics, in 2010 there were 26 individuals seen by a group of 100,000 who were depending in home oxygen therapy (HOT). Oxygen treatment adds a certain amount of Oxygen to the patient because the ability to breathe correctly and sufficiently is negatively affected.

    The dominant disease that leads to HOT is COPD, chronic obstructive pulmonary disease. As the name suggests, it is a chronic disease which gives inflammatory changes to the lung bronchioles. These changes affect the breathing surface which results in that the individuals’ respiratory capacity becomes reduced.

    The project used methods from dynamic product development with the user in focus. This to obtain a functional prototype that could be used by the target group and to fulfill the purpose, goals and requirements set for the project's results. An important component of the project therefore was to work with the collection of data. For this, various methods were used to obtain information from users as well as prescribers of HOT. All of the methods used have been tested earlier and proven reliable. This project collected information from interviews, observations, matrix arrays, risk analysis and usability testing in patients with HOT.

    The prototype developed in the project resulted in that the target group could perform live test without any risks during testing. The results showed that the aim and objective for the project were fulfilled, expressed in that patients would be able to move the oxygen tube used in HOT.

    It was further concluded that the results fulfilled the patients' desire and opportunity to move the Oxygen tube in their home and at the same time answered the questions that the project was to answer. There were no existing solutions to the problem which is included in the project, but it was possible to develop a first prototype that met the purpose and object of the project.

  • 9.
    Carlsson, Markus
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Utvärdering av protesfötter med hjälp av en konstruktion som kan utföra en mekanisk gång.2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This paper has evaluated a new type of prosthetic foot, X-Balance, which aim was to facilitate the performance on uneven ground for the user. This study have performed gait analyzes with three prosthetic feet, the X-Balance, Flex-Foot and assure Ottobock9192 on flat and uneven surfaces using 3D analysis system QTM (Qualisys Track Manager) and associated force plates. During the project a prototype of a design that can perform a mechanical gait were manufactured. The prototype has then been used to fulfill the purpose and objective of this study which is to make different final sets that demonstrate differences between prosthetic feet. Gait analyses of individuals have also been performed to get an idea of what normal gait is. The reliability of the prototype was measured and compared to the study with individuals. By comparison, it could be established that the structure had a higher reliability than the individuals, thus making it easier to compare prosthetic feet against each other. There are no measurements to show that proves that the mechanical gait with the prototype has a high validity. The evaluation findings shows that Ottobock9192 reduce the forces in the Z- and Y-direction most and thus contributes to a gentler heel strike than the other two prosthetics. The results also shows that X-Balance allows greater flexibility in sideway direction (supination) and contributing to a more gentle and easier gait for the user once operate the prosthetic foot over an object with the medial part of the forefoot.

  • 10.
    Carlvik, Fredrik
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Orve, Jacob
    Halmstad University, School of Business, Engineering and Science.
    Unify Xtend: Utveckling av vakuumassisterat suspensionsystem för att reducera skav och glapp vid användning av benprotes2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Lindhe Xtend is a prosthetics company in Halmstad with the ambition of providing the amputee with functional mobility and a high quality of life. Their main product, the Xtend Foot is a patented prosthetic foot developed to imitate the natural features of the human foot.

     

    Dissatisfaction with prostheses often stems from poor fitting of the part that connects to the body. This often leads to chafing, pistoning and strain. Amongst users of leg prostheses, the strain often results in a reduction of limb volume, further augmenting the bad fit. The development of suspension systems has excelled through the recent years as many prosthetics companies has developed products with integrated vacuum assisted suspension systems, a mounting method where vacuum is used to hold the prosthesis against the body. This mounting mechanism of the limb onto the prosthesis has been proven to prevent fluctuations of limb volume as well as reducing chafing and pistoning.

     

    A vacuum assisted suspension system integrated with the Xtend Foot has been invented using the product development process. The project group has used motion analysis, calculations and concept generation to reach a final concept to be prototyped, called Unify Xtend. Unify Xtend is made to demonstrate the function of the final concept, to actively produce a vacuum during ambulation using a pneumatic actuator.

    This project has addressed prosthetics and pneumatics. The project group has, using their knowledge of mechanical engineering and physiology, combined and applied them in this thesis.

    Further user testing is needed to evaluate the usability of the prototype, due to reaching target pressure considerably faster than the products of main market competitors.

  • 11.
    Ekelund, Gustaf
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Andersson, Sebastian
    Halmstad University, School of Business, Engineering and Science.
    Jack The Gripper: Fixationsplatta för typ 3-frakturer på scapula2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Reverse Total Shoulder Arthroplasty (rTSA) is an increasingly common approach to treating different shoulder injuries. The rTSA results in increased force from m. deltoideus which originates from acromion. However, postoperative fractures on the scapula have occurred in some cases. These fractures are divided into 3 different types depending on where the fracture occurs. There is no recommended treatment for type 3 fractures. This project is a product development project with the purpose to find a solution to the fixation problem of type 3 fractures.To reach the project goal, the group has used well-known and proven product development methods, calculations, FEM analyzes and a model assembly analysis. The concept development was performed by interviewing orthopedics who have a lot of experience with rTSA and osteosynthesis related to these fractures. A prototype, which shows the features of the fixation plate, was made using 3D printers.The result of this project has provided a fixation plate that meets the groups requirements and has features that a modern fixation plate has today. In addition, two types of extra plates mounted on the fixation plate to the thin structure of spina scapula, was developed to counteract the axial force. The fixation plate shows excellent results on the FEM analyzes and assembly analysis performed on a scapula model. The prototype has also been given good testimonials from the orthopedics who participated in the project.

  • 12.
    Hellman, Emma
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Sahlström, Fredrik
    Halmstad University, School of Business and Engineering (SET).
    HUTTR - Räddningsfilt för hypoterma patienter2011Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Av de tusentals olyckor som sker varje vinter kan kylan bidra till förödande komplikationer. Vär- meförlust från kroppen kan leda till att personer drabbas av hypotermi. Hypotermi inträffar när en persons kroppstemperatur understiger 35 °C och kroppens värmeproduktion slås ut. De låga kropps- temperaturerna gör det svårare att klara av överlevande aktiviteter så som att andas och att stoppa blödningar. För att förhindra fortsatt nedkylning krävs det att personen skyddas mot värmeförlusten och att extern värme tillförs.

    För några år sedan ändrades riktlinjerna för hur extern värme får tillföras i fält och det blev då tillåtet för räddningspersonal att tillföra värme redan vid olycksplatsen. Dock reagerade inte marknaden på detta direktiv och räddningstjänsten är idag tvungna att använda bristfälliga produkter. Svenska Sjöräddningssällskapet, SSRS, har uttryckt ett stort behov av nya, kompletta lösningar som ger rätt vård till patienten.

    Resterande innehåll i sammanfattningen är sekretesskyddad enligt kapitel 2 då det röjer nyheter som förhindrar patentsökande.

  • 13.
    Jönsson, Anna
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Brettéus, Emily
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    dentÆd: Utveckling av medicintekniskt instrument som ökar säkerheten samt underlättar vid oral protetik.2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The project was initiated by dental personnel at the Specialist dentistry in Halmstad, Sweden, because they experienced problems when working with oral prosthetics. There is a risk that components are dropped and due to gravity and the patient's position, being inhaled or swallowed. This means stress and concerns, contributing to the deterioration of the psychosocial work environment for dental personnel.

     

    The Swedish dental State support was introduced in 2008, which gives the patient a reduced cost for dental prosthetic procedures. This allows more people to afford oral prosthetics. Therefore, the problem becomes more and more prevalent and the demand for a solution is requiered.

     

     The project has implemented dynamic product development with a major focus on the involvement of future users. The project was based on literature reviews, observation and survey, which was performed in the product definition phase. Different concept generation methods and evaluation methods were applied and resulted in a final prototype. A continuous dialogue and testing with the clients where performed throughout the project.

     

    This product development project resulted in an instrument that facilitates for dental personnel and increase safety for the patient during oral prosthetics. The solution is a specially designed forceps which slips onto the screwdriver and secures components.

  • 14.
    Khandelwal, Siddhartha
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Gait Event Detection in the Real World2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Healthy gait requires a balance between various neuro-physiological systems and is considered an important indicator of a subject's physical and cognitive health status. As such, health-related applications would immensely benefit by performing long-term or continuous monitoring of subjects' gait in their natural environment and everyday lives. In contrast to stationary sensors such as motion capture systems and force plates, inertial sensors provide a good alternative for such gait analysis applications as they are miniature, cheap, mobile and can be easily integrated into wearable systems.

    This thesis focuses on improving overall gait analysis using inertial sensors by providing a methodology for detecting gait events in real-world settings. Although the experimental protocols for such analysis have been restricted to only highly-controlled lab-like indoor settings; this thesis presents a new gait database that consists of data from gait activities carried out in both, indoor and outdoor environments. The thesis shows how domain knowledge about gait could be formulated and utilized to develop methods that are robust and can tackle real-world challenges. It also shows how the proposed approach can be generalized to estimate gait events from multiple body locations. Another aspect of this thesis is to demonstrate that the traditionally used temporal error metrics are not enough for presenting the overall performance of gait event detection methods. The thesis introduces how non-parametric tests can be used to complement them and provide a better overview.

    The results of comparing the proposed methodology to state-of-the-art methods showed that the approach of incorporating domain knowledge into the time-frequency analysis of the signal was robust across different real-world scenarios and outperformed other methods, especially for the scenario involving variable gait speeds in outdoor settings. The methodology was also benchmarked on publicly available gait databases yielding good performance for estimating events from different body locations. To conclude, this thesis presents a road map for the development of gait analysis systems in real-world settings.

  • 15.
    Khandelwal, Siddhartha
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Wickström, Nicholas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Identification of Gait Events using Expert Knowledge and Continuous Wavelet Transform Analysis2014In: BIOSIGNALS 2014: Proceedings of the International Conference on Bio-inspired Systems and Signal Processing / [ed] Harald Loose, Guy Plantier, Tanja Schultz, Ana Fred & Hugo Gamboa, [S.l.]: SciTePress, 2014, p. 197-204Conference paper (Refereed)
    Abstract [en]

    Many gait analysis applications involve long-term or continuous monitoring which require gait measurements to be taken outdoors. Wearable inertial sensors like accelerometers have become popular for such applications as they are miniature, low-powered and inexpensive but with the drawback that they are prone to noise and require robust algorithms for precise identification of gait events. However, most gait event detection algorithms have been developed by simulating physical world environments inside controlled laboratories. In this paper, we propose a novel algorithm that robustly and efficiently identifies gait events from accelerometer signals collected during both, indoor and outdoor walking of healthy subjects. The proposed method makes adept use of prior knowledge of walking gait characteristics, referred to as expert knowledge, in conjunction with continuous wavelet transform analysis to detect gait events of heel strike and toe off. It was observed that in comparison to indoor, the outdoor walking acceleration signals were of poorer quality and highly corrupted with noise. The proposed algorithm presents an automated way to effectively analyze such noisy signals in order to identify gait events.

  • 16. Lavesson, Tilde
    Schysst Diabetes: Ett smart webbverktyg för diabetstekniska hjälpmedel.2016Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
  • 17.
    Lindhe, Christoffer
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Klintäng, Anders
    Halmstad University, School of Business and Engineering (SET).
    xBalance: The safer and more comfortable prosthetic foot2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
  • 18.
    Mashad Nemati, Hassan
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Gholami Shahbandi, Saeed
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Åstrand, Björn
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Human Tracking in Occlusion based on Reappearance Event Estimation2016In: ICINCO 2016: 13th International Conference on Informatics in Control, Automation and Robotics: Proceedings, Volume 2 / [ed] Oleg Gusikhin, Dimitri Peaucelle & Kurosh Madani, SciTePress, 2016, Vol. 2, p. 505-512Conference paper (Refereed)
    Abstract [en]

    Relying on the commonsense knowledge that the trajectory of any physical entity in the spatio-temporal domain is continuous, we propose a heuristic data association technique. The technique is used in conjunction with an Extended Kalman Filter (EKF) for human tracking under occlusion. Our method is capable of tracking moving objects, maintain their state hypothesis even in the period of occlusion, and associate the target reappeared from occlusion with the existing hypothesis. The technique relies on the estimation of the reappearance event both in time and location, accompanied with an alert signal that would enable more intelligent behavior (e.g. in path planning). We implemented the proposed method, and evaluated its performance with real-world data. The result validates the expected capabilities, even in case of tracking multiple humans simultaneously.

  • 19.
    Minelga, Jonas
    et al.
    Department of Electric Power Systems, Kaunas University of Technology, Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Vaiciukynas, Evaldas
    Department of Electric Power Systems, Kaunas University of Technology, Kaunas, Lithuania.
    Gelzinis, Adas
    Department of Electric Power Systems, Kaunas University of Technology, Kaunas, Lithuania.
    Bacauskiene, Marija
    Department of Electric Power Systems, Kaunas University of Technology, Kaunas, Lithuania.
    A Transparent Decision Support Tool in Screening for Laryngeal Disorders Using Voice and Query Data2017In: Applied Sciences: APPS, ISSN 1454-5101, E-ISSN 1454-5101, Vol. 7, no 10, p. 1-15, article id 1096Article in journal (Refereed)
    Abstract [en]

    The aim of this study is a transparent tool for analysis of voice (sustained phonation /a/) and query data capable of providing support in screening for laryngeal disorders. In this work, screening is concerned with identification of potentially pathological cases by classifying subject’s data into ’healthy’ and ’pathological’ classes as well as visual exploration of data and automatic decisions. A set of association rules and a decision tree, techniques lending themselves for exploration, were generated for pathology detection. Data pairwise similarities, estimated in a novel way, were mapped onto a 2D metric space for visual inspection and analysis. Accurate identification of pathological cases was observed on unseen subjects using the most discriminative query parameter and six audio parameters routinely used by otolaryngologists in a clinical practice: equal error rate (EER) of 11.1% was achieved using association rules and 10.2% using the decision tree. The EER was further reduced to 9.5% by combining results from these two classifiers. The developed solution can be a useful tool for Otolaryngology departments in diagnostics, education and exploratory tasks. © 2017 by the authors.

  • 20.
    Niemand, Ponthus
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Saladdin, Aya
    Halmstad University, School of Business, Engineering and Science.
    Management of ergonomic aspects in early design phases using virtual reality: Mapping of ergonomic aspects in early design phases, How would mordern technology like VR be used?2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Volvo Group is one of the Worlds leading manufacturer in the categories trucks, busses, construction equipment and engines for the marine and industrial applications. Volvo Group consist of many different brands 10 in total, these are: Volvo Trucks, UD Trucks, Renault Trucks, Mack Trucks, Group Trucks Asia & JVs, Volvo Construction Equipment, Volvo Bus, Volvo Penta, Volvo Financial Services and Governmental Sales. The initiative for the project came from Method and Process Development within Volvo Trucks Tuve Plant, department at Volvo Group Trucks Operations (GTO), which is the part of Volvo Group performing the actual production of the trucks.

    Volvo GTO is located worldwide in several different countries, which leads to different work processes. To standardize a method where the designer (component owner) together with the geometry architect can make a first ergonomics analysis of the concerned component. To make this possible, the project presented a manual on how the component owner should proceed to obtain as good and correct analysis of ergonomics as possible.

    This bachelor thesis makes suggestions for how VR would be helpful in the design phase as an evaluation tool during development of a new product/component or whether improvements should be made to an existing component. The thesis has focused mostly on how the designer and geometry architect can evaluate the ergonomics aspects with VR as a help, already in the design phase.

    The project has investigated two user cases. One of them is presented in this report. This applies to the installation of heat shield, the reason that this particular assembly was chosen is due to its poor ergonomics and accessibility. The project chose to do a RULA-analysis and PLIBEL-analysis. The RULA analysis gave a high total score, 7 out of 7, while PLIBEL was an analysis at the workplace. Both proved to be a good basis for continued work. 

    The study shows that VR is a great tool for analysis of the ergonomics aspects in early design phase. It gives relevant results and has the potential for savings in resources and cost in product development process.

    To improve the results of the thesis, there have been visits on ESI-Group which has sponsored the thesis in the form of VR equipment and workshop. This gave the project members an insight into the possibilities of VR.

  • 21.
    Nilsson, Andreas
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Almén, Martin
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Sundström, Johan
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Sond för mätning av tandfickors djup2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis work was made in autumn 2011 and was commissioned by Accesia AB, whowanted to develop a prototype of an electronic tool for measuring periodontal pockets depth.The tool is supposed to be used in veterinary dental examinations for dogs and cats. This is aprocedure that is currently done with a graded stick and gives rise to the risk of false readings.The user should be able to use the measuring equipment to measure pocket depthelectronically. The system then presents readings and sends them to a host computer.The report describes how we have proceeded from idea to prototype. The end result should notbe regarded as a finished product, but rather as a proof of concept. The result complies with theproject specification that was developed in consultation with the project client.

  • 22.
    Nilsson, Kenneth
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Bigun, Josef
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Prominent symmetry points as landmarks in fingerprint images for alignment2002In: 16th International Conference on Pattern Recognition (ICPR'02) - Proceedings, Volume 3, Piscataway: IEEE Computer Society, 2002, Vol. III, p. 395-398Conference paper (Other academic)
    Abstract [en]

    For the alignment of two fing erprints position of certain landmarks are needed. These should be automatically extracted with low misidentification rate. As landmarks we suggest the prominent symmetry points (core-points) in the fing erprint. They are extracted from the complex orientation field estimated from the global structure of the fingerprint, i.e. the overall pattern of the ridges and valleys. Complex filter s, applied to the orientation field in multiple resolution scales, are used to detect the symmetry and the type of symmetry. Experimental results are reported.

  • 23.
    Norell Pejner, Margaretha
    et al.
    Halmstad University, School of Health and Welfare, Centre of Research on Welfare, Health and Sport (CVHI).
    Lundström, Jens
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Ourique de Morais, Wagner
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Laurell, Hélène
    Halmstad University, School of Business, Engineering and Science, Centre for Innovation, Entrepreneurship and Learning Research (CIEL), Centre for International Marketing and Entrepreneurship Research (CIMER).
    Isaksson, Anna
    Halmstad University, School of Education, Humanities and Social Science, Centrum för lärande, kultur och samhälle (CLKS), Språk, kultur och samhälle.
    Stranne, Frida
    Halmstad University, School of Education, Humanities and Social Science, Centrum för lärande, kultur och samhälle (CLKS).
    Skärsäter, Ingela
    Halmstad University, School of Health and Welfare, Centre of Research on Welfare, Health and Sport (CVHI).
    Smart medication organizer – one way to promote self-management and safety in drug administration in elderly people2017Conference paper (Refereed)
  • 24.
    Persson, Lukas
    et al.
    Halmstad University.
    Norén, Johan
    HållRätt: -Hjälp dig hjälpa dig själv Utveckling av ett hållningshjälpmedel för vardagligt bruk2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Society is becoming increasingly digitalized and we spend more and more of awake hours infront electronics, both at home and at work. Our bodies, made for being resilient hunters, are not suited for sitting still an entire day. The static work exhausts the muscles and makes it hard to maintain a correct posture throughout the day, enough time in static positions may result in both interior and exterior damages to the body. The main purposes with the project is to increase the awareness of what horrible consequences that may occur when the body is being exposed to an unhealthy posture, also develop a prototype for a product that will guide the user on the road of getting a better default posture.The product we have developed is primarily aimed at companies, which it will be able to offer their employees a better shot at a healthier life, which will result in reduced number of sick leaves for the companies. We, Johan Norén and Lukas Persson, has in our thesis, HållRätt, developed a prototype for a product that will assist you by encouraging you to improve your posture reduce your chances of getting unwanted injuries. The product is a wearable accessory that will be undetectable by your surroundings, unless you choose to wear over your clothes. The product will be a combination of a helper and personal trainer who will guide the user on the way to a better posture and thus better health and a fuller life.

  • 25.
    Possfelt, Sofia
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Bertilsson, Alfred
    Halmstad University, School of Business, Engineering and Science.
    D4Active: Diabetes System2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    What is missing today on the Swedish market for diabetic products?

    Users with diabetes type 1 are today asking for products that will elevate the feeling of freedom and increase the quality of life. Diabetes type 1 is a disease where the pancreas is unable to produce insulin to adjust the level of blood sugar. To keep the value stable is the user in need of external control and insulin injection.

     

    Today’s innovations are activity-based products that will offer high technology solutions. The products require the user to adapt, rather than designing the products for the user. The group have enlightened through extensive analysis the occasions a diabetic person perceive itself as exposed. Physical activity was found as the situation to be the hardest to control their values. They lack support from the physical products. The need of user-friendly products that offers greater options for an active lifestyle with a more sustainable suit was noticed.

     

    The goal of the project has been to create a prototype that can demonstrate the possibility to simplify the treatment of diabetes through connecting three innovative products. The products will only be felt as one whole system by the user. The product caters the basic need of usability to create greater prerequisites for an easier everyday life.

     

    The result of the project consists of a requested prototype of the product developed by the new directive of medical technique, MDR. The system will contribute to reduce excessive units, higher sustainability and greater value for the user. The process of developing have been conjoint with users which creates greater possibility for a higher demand of D4Actives future product.

  • 26.
    Razanskas, Petras
    et al.
    Kaunas University of Technology, Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Olsson, Charlotte
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Wiberg, Per-Arne
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Time Domain Features of Multi-channel EMG Applied to Prediction of Physiological Parameters in Fatiguing Bicycling Exercises2015In: Frontiers in Artificial Intelligence and Applications, ISSN 0922-6389, E-ISSN 1879-8314, Vol. 278, p. 118-127Article in journal (Refereed)
    Abstract [en]

    A set of novel time-domain features characterizing multi-channel surface EMG (sEMG) signals of six muscles (rectus femoris, vastus lateralis, and semitendinosus of each leg) is proposed for prediction of physiological parameters considered important in cycling: blood lactate concentration and oxygen uptake. Fifty one different features, including phase shifts between muscles, active time percentages, sEMG amplitudes, as well as symmetry measures between both legs, were defined from sEMG data and used to train linear and random forest models. The random forests models achieved the coefficient of determination R2 = 0:962 (lactate) and R2 = 0:980 (oxygen). The linear models were less accurate. Feature pruning applied enabled creating accurate random forest models (R2 >0:9) using as few as 7 (lactate) or 4 (oxygen) time-domain features. sEMG amplitude was important for both types of models. Models to predict lactate also relied on measurements describing interaction between front and back muscles, while models to predict oxygen uptake relied on front muscles only, but also included interactions between the two legs. © 2015 The authors and IOS Press. All rights reserved.

  • 27.
    Ražanskas, Petras
    et al.
    Department of Electric Power Systems, Kaunas University of Technology, Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research. Department of Electrical Power Systems, Kaunas University of Technology, Lithuania.
    Viberg, Per-Arne
    Swedish Adrenaline, Halmstad, Sweden.
    Olsson, Charlotte M.
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Predicting physiological parameters in fatiguing bicycling exercises using muscle activation timing2017In: Biomedical Signal Processing and Control, ISSN 1746-8094, E-ISSN 1746-8108, Vol. 35, p. 19-29Article in journal (Refereed)
    Abstract [en]

    This article is concerned with a novel technique for prediction of blood lactate concentration level and oxygen uptake rate from multi-channel surface electromyography (sEMG) signals. The approach is built on predictive models exploiting a set of novel time-domain variables computed from sEMG signals. Signals from three muscles of each leg, namely, vastus lateralis, rectus femoris, and semitendinosus were used in this study. The feature set includes parameters reflecting asymmetry between legs, phase shifts between activation of different muscles, active time percentages, and sEMG amplitude. Prediction ability of both linear and non-linear (random forests-based) models was explored. The random forests models showed very good prediction accuracy and attained the coefficient of determination R2 = 0.962 for lactate concentration level and R2 = 0.980 for oxygen uptake rate. The linear models showed lower prediction accuracy. Comparable results were obtained also when sEMG amplitude data were removed from the training sets. A feature elimination algorithm allowed to build accurate random forests (R2 > 0.9) using just six (lactate concentration level) or four (oxygen uptake rate) time-domain variables. Models created to predict blood lactate concentration rate relied on variables reflecting interaction between front and back leg muscles, while parameters computed from front muscles and interactions between two legs were the most important variables for models created to predict oxygen uptake rate.© 2017 Elsevier Ltd.

  • 28.
    Rosén, Bengt-Göran
    et al.
    Halmstad University, School of Business, Engineering and Science, Mechanical Engineering and Industrial Design (MTEK), Functional Surfaces.
    Wennerberg, Ann
    Malmö Högskola, Odontologiska fakulteten.
    Jimbo, Ryo
    Malmö Högskola, Odontologiska fakulteten.
    Fractal (scale sensitive) characterisation of dental implant morfology2012Conference paper (Other academic)
  • 29.
    Rosén, Stefan
    et al.
    Toponova AB, Halmstad, Sweden.
    Thomas, Tom
    Halmstad University, School of Business, Engineering and Science, Mechanical Engineering and Industrial Design (MTEK).
    Rosén, Bengt-Göran
    Halmstad University, School of Business, Engineering and Science, Mechanical Engineering and Industrial Design (MTEK), Functional Surfaces. Manufacturing Technology Research Group, Department of Materials and Manufacturing Technology, Chalmers University, Göteborg, Sweden.
    The Stedman diagram revisited2014In: Surface Topography : Metrology and Properties, ISSN 2051-672X, Vol. 2, no 1, article id 014005Article in journal (Refereed)
    Abstract [en]

    The Stedman diagram has been used for some years to display aspects of the performance of instruments measuring surface roughness. Such diagrams are herein employed to compare the features of a range of proprietary measuring instruments, including contact and non-contact devices. An extension of the basic diagram is proposed, which would allow it to include a further aspect: the speed of data collection. Figures of merit based on the revised diagram are computed, which enable instruments to be ranked on these particular aspects of their performance. Contact instruments emerge as comparable to non-contact, as their slower rate of data acquisition can be offset by the greater area they can access in amplitude–wavelength space. © 2014 IOP Publishing Ltd.

  • 30.
    Rosén, Stefan
    et al.
    Toponova AB, Halmstad, Sweden.
    Thomas, Tom
    Halmstad University, School of Business, Engineering and Science, Mechanical Engineering and Industrial Design (MTEK), Functional Surfaces.
    Rosén, Bengt-Göran
    Halmstad University, School of Business, Engineering and Science, Mechanical Engineering and Industrial Design (MTEK), Functional Surfaces. Chalmers University, Göteborg, Sweden.
    The Stedman diagram revisited2013In: Metrology and Properties of Engineering Surfaces, 2013: Proceedings of the 14th International Conference, Taipei, Taiwan, June 17-21, 2013, 2013, p. 201-206Conference paper (Refereed)
    Abstract [en]

    The Stedman diagram has been used for some years to display aspects of the performance of surface roughness measuring instruments. Such diagrams are herein employed to compare the features of a range of proprietary measuring instruments, including contact and non-contact devices. An extension of the basic diagram is proposed which would allow it to include a further aspect, speed of data collection. Figures of merit based on the revised diagram are computed which enable instruments to be ranked on these particular aspects of their performance. Contact instruments emerge as comparable to non-contact, as their slower rate of data acquisition can be offset by the greater area they can access in amplitude-wavelength space.

  • 31.
    Salomonsson, Angelica
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Biomechanics and Biomedicine.
    Utveckling av medicintekniskt instrument för mätning av muskelstyrka2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete inom biomekanik var ett produktutvecklingsprojekt av ett medicintekniskt instrument för mätning av statisk muskelstyrka i lårmuskulaturen (quadriceps). Instrumentet utvecklades med utgångspunkt från instrumentet Stig Starke som blivit föråldrat och förfallet. Stig Starke nyttjas främst av sjukgymnaster på Sahlgrenska universitetssjukhuset med syfte att exempelvis utvärdera effekter av sjukgymnastisk behandling. Behovet av en ny version av instrumentet är stort både inom kliniskt arbete och inom forskning. En ny version av instrumentet skulle hjälpa sjukgymnaster och forskare till att kunna fortsätta mäta muskelstyrkan i quadriceps på ett snabbt och enkelt sätt.

    Syftet och målsättningen med detta examensarbete var att utveckla Stig Starke-instrumentet så att mätningar av maximal statisk styrka i lårmuskulaturen (quadriceps), i enheten Newton, kan göras på patienter inom sjukvård och rehabilitering. En problemanalys i form av Workshop gjordes hos användarna på Sahlgrenska universitetssjukhuset. Problemanalysen tillsammans med en förstudie lade grunden för koncept i form av krav och önskemål till nya versionen av instrumentet. Önskemål på användarvänlighet av instrumentet och standardisering av patientens kroppsposition stod högt i prioritering.

    Via dynamisk produktutveckling och biomekaniska metoder där användarna (sjukgymnasterna) var i fokus kunde ett koncept väljas ut och tillverkas till en funktionell prototyp. Sex nyckelord för arbetet är quadriceps, muskelkraft, instrument, antropometri, användarvänlighet och standardisering. Funktionella prototypen visade via produktutvärdering att goda utvecklingsmöjligheter finns för den nya versionen, då den visade på hög användarvänlighet och standardisering. Behovet av en ny version av instrumentet kommer att finnas kvar tills ett likvärdigt instrument som Stig Starke kan tillämpas i verkligheten. 

  • 32.
    Sant'Anna, Anita
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent Systems´ laboratory.
    Wickström, Nicholas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent Systems´ laboratory.
    Eklund, Helene
    Center for Person-Centered Care, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Tranberg, Roy
    Department of Orthopedics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    A wearable gait analysis system using inertial sensors Part II: Evaluation in a clinical setting2012In: BIOSIGNALS 2012 - Proceedings of the International Conference on Bio-Inspired Systems and Signal Processing, [S. l.]: SciTePress, 2012, p. 5-14Conference paper (Refereed)
    Abstract [en]

    The gold standard for gait analysis, in-lab 3D motion capture, is not routinely used for clinical assessment due to limitations in availability, cost and required training. Inexpensive alternatives to quantitative gait analysis are needed to increase the its adoption. Inertial sensors such as accelerometers and gyroscopes are promising tools for the development of wearable gait analysis (WGA) systems. The present study evaluates the use of a WGA system on hip-arthroplasty patients in a real clinical setting. The system provides information about gait symmetry and normality. Results show that the normality measurements are well correlated with various quantitative and qualitative measures of recovery and health status.

  • 33.
    Sant'Anna, Anita
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Wickström, Nicholas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Eklund, Helene
    Sahlgrenska Academy, Göteborg, Sweden.
    Zügner, Roland
    Sahlgrenska Academy, Göteborg, Sweden.
    Tranberg, Roy
    Sahlgrenska Academy, Göteborg, Sweden.
    Assessment of Gait Symmetry and Gait Normality Using Inertial Sensors: In-Lab and In-Situ Evaluation2013In: Biomedical Engineering Systems and Technologies: 5th International Joint Conference, BIOSTEC 2012, Vilamoura, Portugal, February 1-4, 2012, Revised Selected Papers / [ed] Joaquim Gabriel et al., Heidelberg: Springer Berlin/Heidelberg, 2013, p. 239-254Chapter in book (Refereed)
    Abstract [en]

    Quantitative gait analysis is a powerful tool for the assessment of a number of physical and cognitive conditions. Unfortunately, the costs involved in providing in-lab 3D kinematic analysis to all patients is prohibitive. Inertial sensors such as accelerometers and gyroscopes may complement in-lab analysis by providing cheaper gait analysis systems that can be deployed anywhere. The present study investigates the use of inertial sensors to quantify gait symmetry and gait normality. The system was evaluated in-lab, against 3D kinematic measurements; and also in-situ, against clinical assessments of hip-replacement patients. Results show that the system not only correlates well with kinematic measurements but it also corroborates various quantitative and qualitative measures of recovery and health status of hip-replacement patients

  • 34.
    Sant'Anna, Anita
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent Systems´ laboratory.
    Wickström, Nicholas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent Systems´ laboratory.
    Zügner, Roland
    Department of Orthopedics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Tranberg, Roy
    Department of Orthopedics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    A wearable gait analysis system using inertial sensors Part I: Evaluation of measures of gait symmetry and normality against 3D kinematic data2012In: BIOSIGNALS 2012 - Proceedings of the International Conference on Bio-Inspired Systems and Signal Processing, [S. l.]: SciTePress, 2012, p. 180-188Conference paper (Refereed)
    Abstract [en]

    Gait analysis (GA) is an important tool in the assessment of several physical and cognitive conditions. The lack of simple and economically viable quantitative GA systems has hindered the routine clinical use of GA in many areas. As a result, patients may be receiving sub-optimal treatment. The present study introduces and evaluates measures of gait symmetry and gait normality calculated from inertial sensor data. These indices support the creation of mobile, cheap and easy to use quantitative GA systems. The proposed method was compared to measures of symmetry and normality derived from 3D kinematic data. Results show that the proposed method is well correlated to the kinematic analysis in both symmetry (r=0.84, p<0.0001) and normality (r=0.81, p<0.0001). In addition, the proposed indices can be used to classify normal from abnormal gait.

  • 35.
    Sequeira, Ana F.
    et al.
    University of Reading, Reading, United Kingdom.
    Chen, Lulu
    University of Reading, Reading, United Kingdom.
    Wild, Peter
    AIT Austrian Institute of Technology, Vienna, Austria.
    Ferryman, James
    University of Reading, Reading, United Kingdom.
    Alonso-Fernandez, Fernando
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Bigun, Josef
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Raja, Kiran B.
    Norwegian Biometrics Laboratory, NTNU, Gjøvik, Norway.
    Raghavendra, R.
    Norwegian Biometrics Laboratory, NTNU, Gjøvik, Norway.
    Busch, Christoph
    Norwegian Biometrics Laboratory, NTNU, Gjøvik, Norway.
    Cross-Eyed: Cross-Spectral Iris/Periocular Recognition Database and Competition2016In: Proceedings of the 15th International Conference of the Biometrics Special Interest Group / [ed] Arslan Brömme, Christoph Busch, Christian Rathgeb & Andreas Uhl, Piscataway, N.J.: IEEE, 2016Conference paper (Refereed)
    Abstract [en]

    This work presents a novel dual-spectrum database containing both iris and periocular images synchronously captured from a distance and within a realistic indoor environment. This database was used in the 1st Cross-Spectrum Iris/Periocular Recognition Competition (Cross-Eyed 2016). This competition aimed at recording recent advances in cross- spectrum iris and periocular recognition. Six submissions were evaluated for cross-spectrum periocular recognition, and three for iris recognition. The submitted algorithms are briefly introduced. Detailed results are reported in this paper, and comparison of the results is discussed.

  • 36.
    Tahir, Madiha
    et al.
    Mohammad Ali Jinnah University, Islamabad, Pakistan.
    Ul-Abdin, Zain
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). TeleSehat Private Limited, Islamabad, Pakistan.
    Qadir, Muhammad Abdul
    Mohammad Ali Jinnah University, Islamabad, Pakistan.
    Enhancing the HEVC Video Analyzer for Medical Diagnostic Videos2015In: 2015 12th International Conference on High-capacity Optical Networks and Enabling/Emerging Technologies (HONET), [S.l.]: IEEE , 2015, p. 65-69, article id 7395417Conference paper (Refereed)
    Abstract [en]

    Video analyzers are employed to perform an in depth analysis of coding decisions undertaken during the execution of a video codec. Medical diagnostic videos, which are typically dealt with in telemedicine scenarios need careful examination to incorporate the most optimum coding decisions. This paper deals with the enhancement of an open-source video stream analyzer to facilitate codec development tailored for medical diagnostic videos. The proposed extensions include visual representation of quantitative information for the bit count used at CTU level, as well as displaying the different mode decisions adopted in the case of merge mode, prediction mode, and intra mode. We have incorporated the said extensions in HEVC analyzer and validated the approach by using test video sequences for Ultrasound, Eye, and Skin examination. © 2015 IEEE.

  • 37.
    Teng, Xudong
    et al.
    Shanghai University of Engineering Science, Shanghai, China & Nanjing University, Nanjing, China.
    Fan, Yuantao
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Nowaczyk, Sławomir
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent Systems´ laboratory.
    Evaluation of Micro-flaws in Metallic Material Based on A Self-Organized Data-driven Approach2016In: 2016 IEEE International Conference on Prognostics and Health Management (ICPHM), IEEE conference proceedings, 2016Conference paper (Refereed)
    Abstract [en]

    Evaluating the health condition of a material that could potentially contain micro-flaws is a common and important application within the field of non-destructive testing. Examples of such micro-defects include dislocation, fatigue cracks or impurities and are often hard to detect. The ability to precisely measure their type, size and position is a prerequisite for estimating the remaining useful life of the component. One technique that was shown successful in the past is based on traditional ultrasonic testing methods. In most cases, inner micro-flaws induce slight changes of acoustic wave spectrum components. However, these changes are often difficult to detect directly, as they tend to exhibit features that are most naturally analyzed using statistical and probabilistic methods. In this paper we apply Consensus Self-Organizing Models (COSMO) method to detect micro-flaws in metallic material. This approach is essentially an unsupervised deviation detection method based on the concept of "wisdom of the crowd". This method is used to analyze the spectrum of acoustic waves received by the transducer attached on the surface of material being analyzed. We have modeled a steel board with micro-cracks and collected time-series of acoustic echo response, at different positions on material's surface. The experimental results show that the COSMO method is able to detect and locate micro-flaws. © 2016 IEEE

  • 38.
    Uloza, Virgilijus
    et al.
    Lithuanian University of Health Sciences, Kaunas, Lithuania.
    Padervinskis, Evaldas
    Lithuanian University of Health Sciences, Kaunas, Lithuania.
    Uloziene, Ingrida
    Lithuanian University of Health Sciences, Kaunas, Lithuania.
    Saferis, Viktoras
    Lithuanian University of Health Sciences, Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research. Kaunas University of Technology, Kaunas, Lithuania.
    Combined Use of Standard and Throat Microphones for Measurement of Acoustic Voice Parameters and Voice Categorization2015In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 29, no 5, p. 552-559Article in journal (Refereed)
    Abstract [en]

    Summary: Objective. The aim of the present study was to evaluate the reliability of the measurements of acoustic voice parameters obtained simultaneously using oral and contact (throat) microphones and to investigate utility of combined use of these microphones for voice categorization.

    Materials and Methods. Voice samples of sustained vowel /a/ obtained from 157 subjects (105 healthy and 52 pathological voices) were recorded in a soundproof booth simultaneously through two microphones: oral AKG Perception 220 microphone (AKG Acoustics, Vienna, Austria) and contact (throat) Triumph PC microphone (Clearer Communications, Inc, Burnaby, Canada) placed on the lamina of thyroid cartilage. Acoustic voice signal data were measured for fundamental frequency, percent of jitter and shimmer, normalized noise energy, signal-to-noise ratio, and harmonic-to-noise ratio using Dr. Speech software (Tiger Electronics, Seattle, WA).

    Results. The correlations of acoustic voice parameters in vocal performance were statistically significant and strong (r = 0.71–1.0) for the entire functional measurements obtained for the two microphones. When classifying into healthy-pathological voice classes, the oral-shimmer revealed the correct classification rate (CCR) of 75.2% and the throat-jitter revealed CCR of 70.7%. However, combination of both throat and oral microphones allowed identifying a set of three voice parameters: throat-signal-to-noise ratio, oral-shimmer, and oral-normalized noise energy, which provided the CCR of 80.3%.

    Conclusions. The measurements of acoustic voice parameters using a combination of oral and throat microphones showed to be reliable in clinical settings and demonstrated high CCRs when distinguishing the healthy and pathological voice patient groups. Our study validates the suitability of the throat microphone signal for the task of automatic voice analysis for the purpose of voice screening. Copyright © 2014 The Voice Foundation.

  • 39.
    Vedantha Krishna, Amogh
    et al.
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Flys, Olena
    Reddy, Vijeth Venkataram
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Rosén, Bengt Göran
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Surface topography characterization using 3D stereoscopic reconstruction of SEM images2018In: Surface Topography: Metrology and Properties, ISSN 2051-672X, Vol. 6, no 2, article id 024006Article in journal (Refereed)
    Abstract [en]

    A major drawback of the optical microscope is its limitation to resolve finer details. Many microscopes have been developed to overcome the limitations set by the diffraction of visible light. The scanning electron microscope (SEM) is one such alternative: it uses electrons for imaging, which have much smaller wavelength than photons. As a result high magnification with superior image resolution can be achieved. However, SEM generates 2D images which provide limited data for surface measurements and analysis. Often many research areas require the knowledge of 3D structures as they contribute to a comprehensive understanding of microstructure by allowing effective measurements and qualitative visualization of the samples under study. For this reason, stereo photogrammetry technique is employed to convert SEM images into 3D measurable data. This paper aims to utilize a stereoscopic reconstruction technique as a reliable method for characterization of surface topography. Reconstructed results from SEM images are compared with coherence scanning interferometer (CSI) results obtained by measuring a roughness reference standard sample. This paper presents a method to select the most robust/consistent surface texture parameters that are insensitive to the uncertainties involved in the reconstruction technique itself. Results from the two-stereoscopic reconstruction algorithms are also documented in this paper. © 2018 IOP Publishing Ltd.

  • 40.
    Verikas, Antanas
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab). Kaunas University of Technology, Kaunas, Lithuania.
    Gelzinis, Adas
    Kaunas University of Technology, Kaunas, Lithuania.
    Vaiciukynas, Evaldas
    Kaunas University of Technology, Kaunas, Lithuania.
    Bacauskiene, Marija
    Kaunas University of Technology, Kaunas, Lithuania.
    Minelga, Jonas
    Kaunas University of Technology, Kaunas, Lithuania.
    Hållander, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Uloza, Virgilijus
    Lithuanian University of Health Sciences, Kaunas, Lithuania.
    Padervinskis, Evaldas
    Lithuanian University of Health Sciences, Kaunas, Lithuania.
    Data dependent random forest applied to screening for laryngeal disorders through analysis of sustained phonation: Acoustic versus contact microphone2015In: Medical Engineering and Physics, ISSN 1350-4533, E-ISSN 1873-4030, Vol. 37, no 2, p. 210-218Article in journal (Refereed)
    Abstract [en]

    Comprehensive evaluation of results obtained using acoustic and contact microphones in screening for laryngeal disorders through analysis of sustained phonation is the main objective of this study. Aiming to obtain a versatile characterization of voice samples recorded using microphones of both types, 14 different sets of features are extracted and used to build an accurate classifier to distinguish between normal and pathological cases. We propose a new, data dependent random forests-based, way to combine information available from the different feature sets. An approach to exploring data and decisions made by a random forest is also presented. Experimental investigations using a mixed gender database of 273 subjects have shown that the perceptual linear predictive cepstral coefficients (PLPCC) was the best feature set for both microphones. However, the linear predictive coefficients (LPC) and linear predictive cosine transform coefficients (LPCTC) exhibited good performance in the acoustic microphone case only. Models designed using the acoustic microphone data significantly outperformed the ones built using data recorded by the contact microphone. The contact microphone did not bring any additional information useful for the classification. The proposed data dependent random forest significantly outperformed the traditional random forest. (C) 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

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