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  • 1.
    Eyre, Sintra
    et al.
    Department of Clinical Nutrition, Institute of Medicine Sahlgrenska University Hospital Gothenburg Sweden.
    Stenberg, Jenny
    Department of Medical Sciences Uppsala University Uppsala Sweden.
    Wallengren, Ola
    Department of Clinical Nutrition, Institute of Medicine Sahlgrenska University Hospital Gothenburg Sweden.
    Keane, David
    Department of Medicine, CÚRAM SFI Research Centre for Medical Devices, HRB‐Clinical Research Facility Galway National University of Ireland Galway Galway Ireland.
    Avesani, Carla M.
    Department of Clinical Science, Intervention and Technology, Division of Renal Medicine and Baxter Novum Karolinska Institutet Solna Sweden.
    Bosaeus, Ingvar
    Department of Clinical Nutrition, Institute of Medicine Sahlgrenska University Hospital Gothenburg Sweden.
    Clyne, Naomi
    Department of Nephrology, Clinical Sciences Skåne University Hospital and Lund University Lund Sweden.
    Heimbürger, Olof
    Department of Clinical Science, Intervention and Technology, Division of Renal Medicine and Baxter Novum Karolinska Institutet Solna Sweden.
    Indurain, Ainhoa
    Department of Kidney Medicine University Hospital Linköping Sweden.
    Johansson, Ann‐Cathrine
    Department of Nephrology Skåne University Hospital Malmö Sweden.
    Lindholm, Bengt
    Department of Clinical Science, Intervention and Technology, Division of Renal Medicine and Baxter Novum Karolinska Institutet Solna Sweden.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Department of Clinical Science, Intervention and Technology Karolinska Institutet Stockholm Sweden;Department of Medical Technology Karolinska University Hospital Stockholm Sweden;Department of Clinical Physiology Karolinska University Hospital Stockholm Sweden;Department of Textile Technology University of Borås Borås Sweden.
    Trondsen, Mia
    Department of Nephrology Skåne University Hospital Malmö Sweden.
    Bioimpedance analysis in patients with chronic kidney disease2023Ingår i: Journal of Renal Care, ISSN 1755-6678, E-ISSN 1755-6686, Vol. 49, nr 3, s. 147-157Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    In recent years the use of bioimpedance analysis (BIA) for assessment of fluid status as well as body composition as a mean to assess nutritional status in CKD has increased. The interest in the method is due to the associations between fluid overload and cardiovascular disease, and between fluid overload and malnutrition, both of which contribute to an increased risk of morbidity and mortality (Hur et al., 2013; Onofriescu et al., 2014). Moreover, BIA devices are suitable for clinical use, since they are portable, easy to use and, with a median to low price. However, the results can be difficult to interpret and integrate into routine clinical care, and although impedance measurements can contribute to an increased understanding of the patient's fluid balance, the results should be used with caution and in combination with other physiological parameters and clinical assessments (de Ruiter et al., 2020; Scotland et al., 2018). The aim of this editorial is to contribute to increased awareness of the benefits and limitations of using bioimpedance in patients with CKD with or without dialysis, and contribute to improving the measurement quality, facilitating interpretations, and highlighting possible sources of error.

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  • 2. Fernandez-Llatas, Carlos
    et al.
    Gatta, Roberto
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Valentini, Vincenzo
    Editorial: Artificial intelligence in process modelling in oncology2023Ingår i: Frontiers in Oncology, E-ISSN 2234-943X, Vol. 13Artikel i tidskrift (Övrigt vetenskapligt)
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  • 3.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden; Department of Medical Technology, Karolinska University Hospital, Stockholm, Sweden.
    Yang, Lin
    Department of Aerospace Medicine, Fourth Military Medical University, Xi’an, China.
    Dai, Meng
    Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China.
    Zhao, Zhangqi
    Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany.
    Multidimensional physiology: novel techniques and discoveries with bioimpedance measurements2023Ingår i: Frontiers in Physiology, E-ISSN 1664-042X, Vol. 14, artikel-id 1243850Artikel i tidskrift (Refereegranskat)
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  • 4.
    Simic, M.
    et al.
    Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia.
    Freeborn, T. J.
    Todd J. Freeborn Department of Electrical and Computer Engineering, The University of Alabama, Tuscaloosa, AL, USA.
    Veletic, M.
    Department of Electronic Systems, Norwegian University of Science and Technology, Trondheim, Norway; The Intervention Centre,Technology and Inno- 525 vation Clinic, Oslo University Hospital, Oslo, Norway.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden; Department of Clinical Physiology and the Department of Medical Technology, Karolinska University Hospital, Stockholm, Sweden.
    Stojanovic, G. M.
    Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia.
    Parameter Estimation of the Single-Dispersion Fractional Cole-Impedance Model With the Embedded Hardware2023Ingår i: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 23, nr 12, s. 12978-12987Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bioimpedance modeling with equivalent electrical circuits has an important role in various biomedical applications, as it facilitates understanding of underlying physical and electrochemical processes in applications such as body composition measurements and assessment of clinical conditions. However, the estimation of model parameter values is not a straightforward task, especially when complex circuits with fractional-order components [e.g., constant phase elements (CPEs)] are used. In this article, we propose a low-complexity method for parameter estimation of the Cole-impedance model suitable for low-cost embedded hardware (e.g., 8-bit microcontrollers). Our approach uses only the measured real and imaginary impedance, without any specific software package/toolbox, or initial values provided by the user. The proposed method was validated with synthetic (noiseless and noisy) data and experimental right-side, hand-to-foot bioimpedance data from a healthy adult participant. Moreover, the proposed method was compared in terms of accuracy with the recently published relevant work and commercial Electrical Impedance Spectroscopy software (Bioimp 2.3.4). The performance evaluation in terms of complexity (suitable for deployment for the microcontroller-based platform with 256 kB of RAM and 16 MHz clock speed), execution time (18 s for the dataset with 256 points), and cost (< 25) confirms the proposed method in regards to reliable bioimpedance processing using embedded hardware. 

  • 5. Chen, Kaile
    et al.
    Abtahi, Farhad
    Carrero, Juan-Jesus
    Fernandez-Llatas, Carlos
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Process mining and data mining applications in the domain of chronic diseases: A systematic review2023Ingår i: Artificial Intelligence in Medicine, ISSN 0933-3657, E-ISSN 1873-2860, Vol. 144, artikel-id 102645Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The widespread use of information technology in healthcare leads to extensive data collection, which can be utilised to enhance patient care and manage chronic illnesses. Our objective is to summarise previous studies that have used data mining or process mining methods in the context of chronic diseases in order to identify research trends and future opportunities. The review covers articles that pertain to the application of data mining or process mining methods on chronic diseases that were published between 2000 and 2022. Articles were sourced from PubMed, Web of Science, EMBASE, and Google Scholar based on predetermined inclusion and exclusion criteria. A total of 71 articles met the inclusion criteria and were included in the review. Based on the literature review results, we detected a growing trend in the application of data mining methods in diabetes research.

    Additionally, a distinct increase in the use of process mining methods to model clinical pathways in cancer research was observed. Frequently, this takes the form of a collaborative integration of process mining, data mining, and traditional statistical methods. In light of this collaborative approach, the meticulous selection of statistical methods based on their underlying assumptions is essential when integrating these traditional methods with process mining and data mining methods. Another notable challenge is the lack of standardised guidelines for reporting process mining studies in the medical field. Furthermore, there is a pressing need to enhance the clinical interpretation of data mining and process mining results.

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  • 6.
    Gunnarsson, Emanuel
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seamlessly integrated textile electrodes and conductive routing in a garment for electrostimulation: design, manufacturing and evaluation2023Ingår i: Scientific Reports, E-ISSN 2045-2322, Vol. 13, artikel-id 17408Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electro-stimulation to alleviate spasticity, pain and to increase mobility has been used successfully for years. Usually, gelled electrodes are used for this. In a garment intended for repeated use such electrodes must be replaced. The Mollii-suit by the company Inerventions utilises dry conductive rubber electrodes. The electrodes work satisfactory, but the garment is cumbersome to fit on the body. In this paper we show that knitted dry electrodes can be used instead. The knitted electrodes present a lower friction against the skin and a garment is easily fitted to the body. The fabric is stretchable and provides a tight fit to the body ensuring electrical contact. We present three candidate textrodes and show how we choose the one with most favourable features for producing the garment. We validate the performance of the garment by measuring three electrical parameters: rise time (10–90%) of the applied voltage, net injected charge and the low frequency value of the skin–electrode impedance. It is concluded that the use of flat knitting intarsia technique can produce a garment with seamlessly integrated conductive leads and electrodes and that this garment delivers energy to the body as targeted and is beneficial from manufacturing and comfort perspectives.

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  • 7.
    Hafid, Abdelakram
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Textile Materials Technology, Department of Textile Technology, Faculty of Textiles, Engineering and Business Swedish School of Textiles, University of Borås, 503 32 Borås, Sweden;School of Innovation, Design and Engineering, Mälardalen University, 722 20 Västerås, Sweden.
    Gunnarsson, Emanuel
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Textile Materials Technology, Department of Textile Technology, Faculty of Textiles, Engineering and Business Swedish School of Textiles, University of Borås, 503 32 Borås, Sweden.
    Ramos, Alberto
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Textile Materials Technology, Department of Textile Technology, Faculty of Textiles, Engineering and Business Swedish School of Textiles, University of Borås, 503 32 Borås, Sweden;UDIT—University of Design, Innovation and Technology, 28016 Madrid, Spain.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Textile Materials Technology, Department of Textile Technology, Faculty of Textiles, Engineering and Business Swedish School of Textiles, University of Borås, 503 32 Borås, Sweden.
    Abtahi, Farhad
    Institute for Clinical Science, Intervention and Technology, Karolinska Institutet, 141 83 Stockholm, Sweden;Department of Medical Care Technology, Karolinska University Hospital, 141 57 Huddinge, Sweden;Department of Clinical Physiology, Karolinska University Hospital, 141 57 Huddinge, Sweden.
    Bamidis, Panagiotis D.
    Lab of Medical Physics and Digital Innovation, School of Medicine, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
    Billis, Antonis
    Lab of Medical Physics and Digital Innovation, School of Medicine, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
    Papachristou, Panagiotis
    Academic Primary Health Care Center, Region Stockholm, 104 31 Stockholm, Sweden;Division of Family Medicine and Primary Care, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 141 83 Stockholm, Sweden.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Textile Materials Technology, Department of Textile Technology, Faculty of Textiles, Engineering and Business Swedish School of Textiles, University of Borås, 503 32 Borås, Sweden;Institute for Clinical Science, Intervention and Technology, Karolinska Institutet, 141 83 Stockholm, Sweden;Department of Medical Care Technology, Karolinska University Hospital, 141 57 Huddinge, Sweden;Department of Clinical Physiology, Karolinska University Hospital, 141 57 Huddinge, Sweden.
    Sensorized T-Shirt with Intarsia-Knitted Conductive Textile Integrated Interconnections: Performance Assessment of Cardiac Measurements during Daily Living Activities2023Ingår i: Sensors, E-ISSN 1424-8220, Vol. 23, nr 22, artikel-id 9208Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The development of smart wearable solutions for monitoring daily life health status is increasingly popular, with chest straps and wristbands being predominant. This study introduces a novel sensorized T-shirt design with textile electrodes connected via a knitting technique to a Movesense device. We aimed to investigate the impact of stationary and movement actions on electrocardiography (ECG) and heart rate (HR) measurements using our sensorized T-shirt. Various activities of daily living (ADLs), including sitting, standing, walking, and mopping, were evaluated by comparing our T-shirt with a commercial chest strap. Our findings demonstrate measurement equivalence across ADLs, regardless of the sensing approach. By comparing ECG and HR measurements, we gained valuable insights into the influence of physical activity on sensorized T-shirt development for monitoring. Notably, the ECG signals exhibited remarkable similarity between our sensorized T-shirt and the chest strap, with closely aligned HR distributions during both stationary and movement actions. The average mean absolute percentage error was below 3%, affirming the agreement between the two solutions. These findings underscore the robustness and accuracy of our sensorized T-shirt in monitoring ECG and HR during diverse ADLs, emphasizing the significance of considering physical activity in cardiovascular monitoring research and the development of personal health applications. 

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  • 8.
    Illueca Fernández, Eduardo
    et al.
    Department of Informatics and Systems, University of Murcia, Murcia, Spain.
    Fernández Llatas, Carlos
    Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm.
    Jara Valera, Antonio Jesús
    Research and Development, HOP Ubiquitous S.L. (Libelium Murcia), Ceutí, Spain .
    Fernández Breis, Jesualdo Tomás
    Department of Informatics and Systems, University of Murcia, Murcia, Spain .
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden, Department of Medical Technology, Karolinska University Hospital, Stockholm, Sweden, Department of Textile Technology, University of Borås, Borås, Sweden, Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden.
    Sequence-oriented sensitive analysis for PM2.5 exposure and risk assessment using interactive process mining2023Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 18, nr 8, s. e0290372-e0290372Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The World Health Organization has estimated that air pollution will be one of the most significant challenges related to the environment in the following years, and air quality monitoring and climate change mitigation actions have been promoted due to the Paris Agreement because of their impact on mortality risk. Thus, generating a methodology that supports experts in making decisions based on exposure data, identifying exposure-related activities, and proposing mitigation scenarios is essential. In this context, the emergence of Interactive Process Mining—a discipline that has progressed in the last years in healthcare—could help to develop a methodology based on human knowledge. For this reason, we propose a new methodology for a sequence-oriented sensitive analysis to identify the best activities and parameters to offer a mitigation policy. This methodology is innovative in the following points: i) we present in this paper the first application of Interactive Process Mining pollution personal exposure mitigation; ii) our solution reduces the computation cost and time of the traditional sensitive analysis; iii) the methodology is human-oriented in the sense that the process should be done with the environmental expert; and iv) our solution has been tested with synthetic data to explore the viability before the move to physical exposure measurements, taking the city of Valencia as the use case, and overcoming the difficulty of performing exposure measurements. This dataset has been generated with a model that considers the city of Valencia’s demographic and epidemiological statistics. We have demonstrated that the assessments done using sequence-oriented sensitive analysis can identify target activities. The proposed scenarios can improve the initial KPIs—in the best scenario; we reduce the population exposure by 18% and the relative risk by 12%. Consequently, our proposal could be used with real data in future steps, becoming an innovative point for air pollution mitigation and environmental improvement.

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  • 9.
    Jacobsson, Martin
    et al.
    Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, Huddinge, Sweden.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden; Department of Clinical Physiology, Karolinska University Hospital Huddinge, Sweden; Department of Textile Technology, University of Borås, Sweden; Department of Medical Technology - Management and Development, Karolinska University Hospital, Sweden..
    Abtahi, Farhad
    Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, Huddinge, Sweden; Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Sweden; Department of Clinical Physiology, Karolinska University Hospital Huddinge, Sweden.
    The role of compression in large scale data transfer and storage of typical biomedical signals at hospitals2023Ingår i: Health Informatics Journal, ISSN 1460-4582, E-ISSN 1741-2811, Vol. 29, nr 4Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In modern hospitals, monitoring patients' vital signs and other biomedical signals is standard practice. With the advent of data-driven healthcare, Internet of medical things, wearable technologies, and machine learning, we expect this to accelerate and to be used in new and promising ways, including early warning systems and precision diagnostics. Hence, we see an ever-increasing need for retrieving, storing, and managing the large amount of biomedical signal data generated. The popularity of standards, such as HL7 FHIR for interoperability and data transfer, have also resulted in their use as a data storage model, which is inefficient. This article raises concern about the inefficiency of using FHIR for storage of biomedical signals and instead highlights the possibility of a sustainable storage based on data compression. Most reported efforts have focused on ECG signals; however, many other typical biomedical signals are understudied. In this article, we are considering arterial blood pressure, photoplethysmography, and respiration. We focus on simple lossless compression with low implementation complexity, low compression delay, and good compression ratios suitable for wide adoption. Our results show that it is easy to obtain a compression ratio of 2.7:1 for arterial blood pressure, 2.9:1 for photoplethysmography, and 4.1:1 for respiration. 

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  • 10. Gunnarsson, Emanuel
    et al.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Three-lead in vivo measurement method for determining the skin-electrode impedance of textile electrodes: A fast, accurate and easy-to-use measurement method suitable for characterization of textile electrodes2023Ingår i: Textile research journal, ISSN 0040-5175, E-ISSN 1746-7748Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The rise of interest in wearable sensing of bioelectrical signals conducted via smart textile systems over the past decades has resulted in many investigations on how to develop and evaluate such systems. All measurements of bioelectrical signals are done by way of electrodes. The most critical parameter for an electrode is the skin-electrode impedance. A common method for measuring skin-electrode impedance is the two-lead method, but it has limitations because it relies on assumptions of symmetries of the body impedance in different parts of the body as well as of the skin-electrode impedances. To address this, in this paper we present an easy-to-use and reliable three-lead in vivo method as a more accurate alternative. We aim to show that the in vivo three-lead method overcomes all such limitations. We aim at raising the awareness regarding the possibility to characterize textile electrodes using a correct, accurate and robust method rather than limited and sometimes inadequate and uninformative methods. The three-lead in vivo method eliminates the effect of body impedance as well as all other contact impedances during measurements. The method is direct and measures only the skin-electrode impedance. This method is suitable for characterization of skin-electrode interface of textile electrodes intended for both bioelectrical signals as well as for electrostimulation of the human body. We foresee that the utilization of the three-lead in vivo method has the potential to impact the further development of wearable sensing by enabling more accurate and reliable measurement of bioelectrical signals. 

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  • 11.
    Benouar, Sara
    et al.
    Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; Laboratory of Instrumentation, Department of Instrumentation and Automatics, Institute of Electrical Engineering, University of Sciences and Technology Houari Boumediene, Bab Ezzouar, Algeria.
    Kedir-Talha, Malika
    Laboratory of Instrumentation, Department of Instrumentation and Automatics, Institute of Electrical Engineering, University of Sciences and Technology Houari Boumediene, Bab Ezzouar, Algeria.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; Department of Medical Technology, Karolinska University Hospital, Stockholm, Sweden; Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden; Department of Textile Technology, University of Borås, Borås, Sweden.
    Time-series NARX feedback neural network for forecasting impedance cardiography ICG missing points: a predictive model2023Ingår i: Frontiers in Physiology, E-ISSN 1664-042X, Vol. 14, artikel-id 1181745Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One of the crucial steps in assessing hemodynamic parameters using impedance cardiography (ICG) is the detection of the characteristic points in the dZ/dt ICG complex, especially the X point. The most often estimated parameters from the ICG complex are stroke volume and cardiac output, for which is required the left ventricular pre-ejection time. Unfortunately, for beat-to-beat calculations, the accuracy of detection is affected by the variability of the ICG complex subtypes. Thus, in this work, we aim to create a predictive model that can predict the missing points and decrease the previous work percentages of missing points to support the detection of ICG characteristic points and the extraction of hemodynamic parameters according to several existing subtypes. Thus, a time-series non-linear autoregressive model with exogenous inputs (NARX) feedback neural network approach was implemented to forecast the missing ICG points according to the different existing subtypes. The NARX was trained on two different datasets with an open-loop mode to ensure that the network is fed with correct feedback inputs. Once the training is satisfactory, the loop can be closed for multi-step prediction tests and simulation. The results show that we can predict the missing characteristic points in all the complexes with a success rate ranging between 75% and 88% in the evaluated datasets. Previously, without the NARX predictive model, the successful detection rate was 21%–30% for the same datasets. Thus, this work indicates a promising method and an accuracy increase in the detection of X, Y, O, and Z points for both datasets.

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  • 12.
    Munoz-Gama, Jorge
    et al.
    Pontificia Universidad Católica de Chile, Chile.
    Martin, Niels
    Hasselt University, Belgium; Research Foundation Flanders (FWO), Belgium.
    Fernandez-Llatas, Carlos
    Universitat Politècnica de València, Spain; Karolinska Institutet, Sweden.
    Johnson, Owen A.
    University of Leeds, United Kingdom.
    Sepúlveda, Marcos
    Pontificia Universidad Católica de Chile, Chile.
    Helm, Emmanuel
    University of Applied Sciences Upper Austria, Austria.
    Galvez-Yanjari, Victor
    Pontificia Universidad Católica de Chile, Chile.
    Rojas, Eric
    Pontificia Universidad Católica de Chile, Chile.
    Martinez-Millana, Antonio
    Universitat Politècnica de València, Spain.
    Aloini, Davide
    University of Pisa, Italy.
    Amantea, Ilaria Angela
    University of Turin, Italy; University of Bologna, Italy; University of Luxembourg, Luxembourg.
    Andrews, Robert
    Queensland University of Technology, Australia.
    Arias, Michael
    Universidad de Costa Rica, Costa Rica.
    Beerepoot, Iris
    Utrecht University, The Netherlands.
    Benevento, Elisabetta
    University of Pisa, Italy.
    Burattin, Andrea
    Technical University of Denmark, Denmark.
    Capurro, Daniel
    University of Melbourne, Australia.
    Carmona, Josep
    Universitat Politècnica de Catalunya, Spain.
    Comuzzi, Marco
    Ulsan National Institute of Science and Technology (UNIST), Republic of Korea.
    Dalmas, Benjamin
    Mines Saint-Etienne, France.
    de la Fuente, Rene
    Pontificia Universidad Católica de Chile, Chile.
    Di Francescomarino, Chiara
    Fondazione Bruno Kessler, Italy.
    Di Ciccio, Claudio
    Sapienza University of Rome, Italy.
    Gatta, Roberto
    Universitá degli Studi di Brescia, Italy.
    Ghidini, Chiara
    Fondazione Bruno Kessler, Italy.
    Gonzalez-Lopez, Fernanda
    Pontificia Universidad Católica de Chile, Chile.
    Ibanez-Sanchez, Gema
    Universitat Politècnica de València, Spain.
    Klasky, Hilda B.
    Oak Ridge National Laboratory, United States.
    Prima Kurniati, Angelina
    Telkom University, Indonesia.
    Lu, Xixi
    Utrecht University, The Netherlands.
    Mannhardt, Felix
    Eindhoven University of Technology, The Netherlands.
    Mans, Ronny
    Philips Research, the Netherlands.
    Marcos, Mar
    Universitat Jaume I, Spain.
    Medeiros de Carvalho, Renata
    Eindhoven University of Technology, The Netherlands.
    Pegoraro, Marco
    RWTH Aachen University, Germany.
    Poon, Simon K.
    The University of Sydney, Australia.
    Pufahl, Luise
    Technische Universitaet Berlin, Germany.
    Reijers, Hajo A.
    Eindhoven University of Technology, The Netherlands; Utrecht University, The Netherlands.
    Remy, Simon
    University of Potsdam, Germany.
    Rinderle-Ma, Stefanie
    Technical University of Munich, Germany.
    Sacchi, Lucia
    University of Pavia, Italy.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Karolinska Institutet, Sweden; Karolinska University Hospital, Sweden.
    Song, Minseok
    Pohang University of Science and Technology, Republic of Korea.
    Stefanini, Alessandro
    University of Pisa, Italy.
    Sulis, Emilio
    University of Turin, Italy.
    ter Hofstede, Arthur H.M.
    Queensland University of Technology, Australia.
    Toussaint, Pieter J.
    Norwegian University of Science and Technology, Norway.
    Traver, Vicente
    Universitat Politècnica de València, Spain.
    Valero-Ramon, Zoe
    Universitat Politècnica de València, Spain.
    Weerd, Inge van de
    Utrecht University, The Netherlands.
    van der Aalst, Wil M.P.
    RWTH Aachen University, Germany.
    Vanwersch, Rob
    Eindhoven University of Technology, The Netherlands.
    Weske, Mathias
    University of Potsdam, Germany.
    Wynn, Moe Thandar
    Queensland University of Technology, Australia.
    Zerbato, Francesca
    University of St. Gallen, Switzerland.
    Process mining for healthcare: Characteristics and challenges2022Ingår i: Journal of Biomedical Informatics, ISSN 1532-0464, E-ISSN 1532-0480, Vol. 127, artikel-id 103994Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Process mining techniques can be used to analyse business processes using the data logged during their execution. These techniques are leveraged in a wide range of domains, including healthcare, where it focuses mainly on the analysis of diagnostic, treatment, and organisational processes. Despite the huge amount of data generated in hospitals by staff and machinery involved in healthcare processes, there is no evidence of a systematic uptake of process mining beyond targeted case studies in a research context. When developing and using process mining in healthcare, distinguishing characteristics of healthcare processes such as their variability and patient-centred focus require targeted attention. Against this background, the Process-Oriented Data Science in Healthcare Alliance has been established to propagate the research and application of techniques targeting the data-driven improvement of healthcare processes. This paper, an initiative of the alliance, presents the distinguishing characteristics of the healthcare domain that need to be considered to successfully use process mining, as well as open challenges that need to be addressed by the community in the future.

  • 13.
    Hafid, Abdelakram
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Mälardalens Högskola.
    Gunnarsson, Emanuel
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Karolinska Institutet.
    Seamless Integration Of Textile-Electronics In Knitted Fabrics For Personalized Health2022Ingår i: Autex conference proceedings, 21st world conference AUTEX 2022, 2022Konferensbidrag (Refereegranskat)
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  • 14.
    Benouar, Sara
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Hafid, Abdelakram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Kedir-Talha, M
    Univ Sci & Technol Houari Boumediene, Lab Instrumentat, Algiers, Algeria.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Classification of impedance cardiography dZ/dt complex subtypes using pattern recognition artificial neural networks2021Ingår i: Biomedizinische Technik (Berlin. Zeitschrift), ISSN 1862-278X, E-ISSN 0013-5585, Vol. 66, nr 5, s. 515-527Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In impedance cardiography (ICG), the detection of dZ/dt signal (ICG) characteristic points, especially the X point, is a crucial step for the calculation of hemodynamic parameters such as stroke volume (SV) and cardiac output (CO). Unfortunately, for beat-to-beat calculations, the accuracy of the detection is affected by the variability of the ICG complex subtypes. Thus, in this work, automated classification of ICG complexes is proposed to support the detection of ICG characteristic points and the extraction of hemodynamic parameters according to several existing subtypes. A novel pattern recognition artificial neural network (PRANN) approach was implemented, and a divide-and-conquer strategy was used to identify the five different waveforms of the ICG complex waveform with output nodes no greater than 3. The PRANN was trained, tested and validated using a dataset from four volunteers from a measurement of eight electrodes. Once the training was satisfactory, the deployed network was validated on two other datasets that were completely different from the training dataset. As an additional performance validation of the PRANN, each dataset included four volunteers for a total of eight volunteers. The results show an average accuracy of 96% in classifying ICG complex subtypes with only a decrease in the accuracy to 83 and 80% on the validation datasets. This work indicates that the PRANN is a promising method for automated classification of ICG subtypes, facilitating the investigation of the extraction of hemodynamic parameters from beat-to-beat dZ/dt complexes.

  • 15.
    Hafid, Abdelakram
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. University of Sciences and Technology Houari Boumediene.
    Benouar, Sara
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. University of Sciences and Technology Houari Boumediene.
    Kedir-Talha, M.
    University of Sciences and Technology Houari Boumediene.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Karolinska Institute.
    Evaluation of dZ/dt Complex Subtypes vs Ensemble Averaging Method for Estimation of Left Ventricular Ejection Time from ICG Recording2021Ingår i: 8th European Medical and Biological Engineering ConferenceProceedings of the EMBEC 2020, November 29 – December 3, 2020 Portorož, Slovenia / [ed] Tomaz Jarm; Aleksandra Cvetkoska; Samo Mahnič-Kalamiza; Damijan Miklavcic, Springer Science and Business Media Deutschland GmbH , 2021, s. 502-509Konferensbidrag (Refereegranskat)
    Abstract [en]

    Impedance cardiography (ICG) was discovered nearly half a century ago, being proposed as noninvasive monitoring method for estimation of several hemodynamics parameter. Despite of nearly 5 decades of clinical research and use there is still certain controversy about its performance when estimating Left Ventricular Ejection Time (LVET). This work present a comparison between using the different ICG subtype waveform and the ensemble averaged (EA) method to calculate the LVET. The ICG has been recorded from four volunteers, and the LVET parameter has been calculated using the two approaches. The result shows that each volunteer have different percentage of subtypes, and the mean relative error between the two approaches for estimation of LVET varied between 0.62 to 2.9% with an average mean absolute percentage error of 18,02% ranging between 13.82 to 18.42%. © 2021, Springer Nature Switzerland AG.

  • 16.
    Benouar, Sara
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. University of Sciences and Technology Houari Boumediene.
    Hafid, Abdelakram
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. University of Sciences and Technology Houari Boumediene.
    Kedir-Talha, M.
    University of Sciences and Technology Houari Boumediene.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Karolinska University Hospital.
    First Steps Toward Automated Classification of Impedance Cardiography dZ/dt Complex Subtypes2021Ingår i: 8th European Medical and Biological Engineering Conference: Proceedings of the EMBEC 2020, November 29 – December 3, 2020 Portorož, Slovenia, Springer Science and Business Media Deutschland GmbH , 2021, s. 563-573Konferensbidrag (Refereegranskat)
    Abstract [en]

    The detection of the characteristic points of the complex of the impedance cardiography (ICG) is a crucial step for the calculation of hemodynamical parameters such as left ventricular ejection time, stroke volume and cardiac output. Extracting the characteristic points from the dZ/dt ICG signal is usually affected by the variability of the ICG complex and assembling average is the method of choice to smooth out such variability. To avoid the use of assembling average that might filter out information relevant for the hemodynamic assessment requires extracting the characteristics points from the different subtypes of the ICG complex. Thus, as a first step to automatize the extraction parameters, the aim of this work is to detect automatically the kind of dZ/dt complex present in the ICG signal. To do so artificial neural networks have been designed with two different configurations for pattern matching (PRANN) and tested to identify the 6 different ICG complex subtypes. One of the configurations implements a 6-classes classifier and the other implemented the divide and conquer approach classifying in two stages. The data sets used in the training, validation and testing process of the PRANNs includes a matrix of 1 s windows of the ICG complexes from the 60 s long recordings of dZ/dt signal for each of the 4 healthy male volunteers. A total of 240 s. As a result, the divide and conquer approach improve the overall classification obtained with the one stage approach on +26% reaching and average classification ration of 82%.

  • 17.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Traver, Vicente
    Process Mining 4 Health Lab – SABIEN – ITACA Institute, Universitat Politècnica de València, Valencia, Spain.
    Hazelzet, Jan
    Erasmus Medical Center, Rotterdam, Netherlands.
    Value-driven digital transformation in health and medical care2021Ingår i: Interactive Process Mining in Healthcare / [ed] Carlos Fernandez-Llatas, Cham: Springer Nature, 2021, s. 13-26Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Medical care has been patient centred from the origin and has evolved closely along the evolution of patient needs from the patient as individual to the patient as population, pursuing to provide the medical care of the highest quality standard, and including a public health approach. The holistic unification of patient individual health and patient population approaches through health and patient outcomes was predicted in “Measuring Health Outcomes” (Cairns, J. British Medical Journal;313:6) back in 1996. Advancements of information technologies deploying new data-driven services enabled the rising and supports development of novel multidimensional and holistic approaches to health care as: Value-based Health Care (VBHC) and the Quadruple Aim of healthcare. Considering value in VBHC as achieving the best outcomes from the perspective of the patient versus executing the care process needed to achieve these outcomes in the most optimal way. It is of paramount importance to identify and understand the processes to be improved; that will help us in order to be able to improve the outcomes. Digital health tools enable deployment of information services and data analysis technologies like the process mining one, which is precisely adequate for discovery, analysis and optimizing of the operational models underlying the actual care processes.Despite that the undergoing transformational change is pulled by global needs and driven by information technologies, data availability and data science, the journey ahead for digital health transformation is full of all sort of barriers: regulatory, clinical adoption, medical trust, and patient acceptance, requiring a holistic approach.

  • 18.
    Mohino-Herranz, Inma
    et al.
    Department of Signal Theory and Communications, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain.
    Gil-Pita, Roberto
    Department of Signal Theory and Communications, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain.
    Garcia-Gomez, Joaquin
    Department of Signal Theory and Communications, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain.
    Rosa-Zurera, Manuel
    Department of Signal Theory and Communications, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Institute for Clinical Science, Intervention and Technology, Karolinska Institutet, 17177 Solna Stockholm, Sweden; Department of Medical Care Technology, Karolinska University Hospital, 14157 Huddinge, Sweden.
    A Wrapper Feature Selection Algorithm: An Emotional Assessment Using Physiological Recordings from Wearable Sensors2020Ingår i: Sensors, E-ISSN 1424-8220, Vol. 20, nr 1Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Assessing emotional state is an emerging application field boosting research activities on the topic of analysis of non-invasive biosignals to find effective markers to accurately determine the emotional state in real-time. Nowadays using wearable sensors, electrocardiogram and thoracic impedance measurements can be recorded, facilitating analyzing cardiac and respiratory functions directly and autonomic nervous system function indirectly. Such analysis allows distinguishing between different emotional states: neutral, sadness, and disgust. This work was specifically focused on the proposal of a k-fold approach for selecting features while training the classifier that reduces the loss of generalization. The performance of the proposed algorithm used as the selection criterion was compared to the commonly used standard error function. The proposed k-fold approach outperforms the conventional method with 4% hit success rate improvement, reaching an accuracy near to 78%. Moreover, the proposed selection criterion method allows the classifier to produce the best performance using a lower number of features at lower computational cost. A reduced number of features reduces the risk of overfitting while a lower computational cost contributes to implementing real-time systems using wearable electronics.

  • 19.
    Martin, Niels
    et al.
    Research Foundation Flanders (FWO), Belgium.
    De Weerdt, Jochen
    KU Leuven, Belgium.
    Fernandez-Llatas, Carlos
    Universitat Politécnica de Valencia, Spain.
    Gal, Avigdor
    Technion – Israel Institute of Technology, Israel.
    Gatta, Roberto
    Centre Hopitalier Universitaire de Vaudois, Switzerland.
    Ibanez, Gema
    Universitat Politécnica de Valencia, Spain.
    Johnson, Owen
    Leeds University, United Kingdom.
    Mannhardt, Felix
    SINTEF Digital, Norway.
    Marco-Ruiz, Luis
    Nasjonalt Senter for e-helseforskning, Norway.
    Mertens, Steven
    Ghent University, Belgium.
    Munoz-Gama, Jorge
    Pontificia Universidad Católica de Chile, Chile.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Högskolan i Borås, Akademin för textil, teknik och ekonomi. Karolinska Institutet, Sweden.
    Vanthienen, Jan
    KU Leuven, Belgium.
    Wynn, Moe Thandar
    Queensland University of Technology, Australia.
    Boileve, David Baltar
    Hospital Universitario Lucus Augusti, Spain.
    Bergs, Jochen
    Hasselt University, Belgium.
    Joosten-Melis, Mieke
    Radboud UMC, The Netherlands.
    Schretlen, Stijn
    Medtronic Integrated Health Solutions, The Netherlands.
    Van Acker, Bart
    Radboud UMC, The Netherlands.
    Recommendations for enhancing the usability and understandability of process mining in healthcare2020Ingår i: Artificial Intelligence in Medicine, ISSN 0933-3657, E-ISSN 1873-2860, Vol. 109Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Healthcare organizations are confronted with challenges including the contention between tightening budgets and increased care needs. In the light of these challenges, they are becoming increasingly aware of the need to improve their processes to ensure quality of care for patients. To identify process improvement opportunities, a thorough process analysis is required, which can be based on real-life process execution data captured by health information systems. Process mining is a research field that focuses on the development of techniques to extract process-related insights from process execution data, providing valuable and previously unknown information to instigate evidence-based process improvement in healthcare. However, despite the potential of process mining, its uptake in healthcare organizations outside case studies in a research context is rather limited. This observation was the starting point for an international brainstorm seminar. Based on the seminar’s outcomes and with the ambition to stimulate a more widespread use of process mining in healthcare, this paper formulates recommendations to enhance the usability and understandability of process mining in healthcare. These recommendations are mainly targeted towards process mining researchers and the community to consider when developing a new research agenda for process mining in healthcare. Moreover, a limited number of recommendations are directed towards healthcare organizations and health information systems vendors, when shaping an environment to enable the continuous use of process mining.

  • 20.
    Mohino-Herranz, Inma
    et al.
    Department of Signal Theory and Communications, University of Alcala, 28805 Alcala de Henares, Madrid, Spain.
    Gil-Pita, Roberto
    Department of Signal Theory and Communications, University of Alcala, 28805 Alcala de Henares, Madrid, Spain.
    Rosa-Zurera, Manuel
    Department of Signal Theory and Communications, University of Alcala, 28805 Alcala de Henares, Madrid, Spain.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Clinical Science, Intervention an Technology, Karolinska Institutet, 17177 Stockholm, Sweden; Department Biomedical Engineering, Karolinska University Hospital, 14186 Stockholm, Sweden.
    Activity recognition using wearable physiological measurements: Selection of features from a comprehensive literature study2019Ingår i: Sensors, E-ISSN 1424-8220, Vol. 19, nr 24, artikel-id 5524Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Activity and emotion recognition based on physiological signal processing in health care applications is a relevant research field, with promising future and relevant applications, such as health at work or preventive care. This paper carries out a deep analysis of features proposed to extract information from the electrocardiogram, thoracic electrical bioimpedance, and electrodermal activity signals. The activities analyzed are: neutral, emotional, mental and physical. A total number of 533 features are tested for activity recognition, performing a comprehensive study taking into consideration the prediction accuracy, feature calculation, window length, and type of classifier. Feature selection to know the most relevant features from the complete set is implemented using a genetic algorithm, with a different number of features. This study has allowed us to determine the best number of features to obtain a good error probability avoiding over-fitting, and the best subset of features among those proposed in the literature. The lowest error probability that is obtained is 22.2%, with 40 features, a least squares error classifier, and 40 s window length.

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  • 21. Malm, Veronica
    et al.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Nierstrasz, Vincent
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Characterisation of Electrical and Stiffness Properties of Conductive Textile Coatings with Metal Flake-shaped Fillers2019Ingår i: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, nr 21, s. 1-18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Two conductive formulations containing different types of micron-sized metal flakes (silver-coated copper (Cu) and pure silver (Ag)) were characterised and used to form highly electrically conductive coatings (conductors) on plain and base-coated woven fabrics, the latter in an encapsulated construction. With e-textiles as the intended application, the fabric stiffness, in terms of flexural stiffness and sheet resistance (Rsh), after durability testing (laundering and abrasion) was investigated and related to user friendliness and long-term performance. Bare and encapsulated conductors with increasing amounts of deposited solids were fabricated by adjusting the knife coating parameters, such as the coating gap height (5, 20, 50, and 200 μm), which reduced the Rsh, as determined by four-point probe (4PP) measurements; however, this improvement was at the expense of increased flexural stiffness of the coated fabrics. The addition of a melamine derivative (MF) as a cross-linker to the Cu formulation and the encapsulation of both conductor types gave the best trade-off between durability and Rsh, as confirmed by 4PP measurements. However, the infrared camera images revealed the formation of hotspots within the bare conductor matrix, although low resistances (determined by 4PP) and no microstructural defects (determined by SEM) were detected. These results stress the importance of thorough investigation to assure the design of reliable conductors applied on textiles requiring this type of maintenance.

  • 22.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Abtahi, Farhad
    Vega-Barbas, Mario
    Personalized Health and Intelligent Workplaces Transforming Ergonomics: Some Lessons Learnt2019Ingår i: Transforming Ergonomics with Personalized Health and Intelligent Workplaces, Amsterdam: IOS Press, 2019, s. 115-119Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    This section contains lessons learnt mainly from several different projects funded by different private and public financiers. The projects were funded from Swedish national and European financiers. The project consortia had significantly different composition with both public and private partners being national, international or cross-national. All these projects have in common that aimed at integrating Wearable Sensing technologies with Information and Communication Technologies to improve the working environment conditions to avoid the exposure to high risk posture and movements leading to musculoskeletal disorders and increasing the risk of injuries. The origin of these lessons learnt is very broad lessons and have been grouped in the following categories: Information Technology Infrastructure, Data Security and Policy issues; Regulatory and Ethics; Employees concerns, human interactions and dual role users and targets; Body Sensing Networks; and Team Management & Communication.

  • 23.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Soroudi, Azadeh
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lu, Ke
    Nilsson, David
    Nilsson, Marie
    Abtahi, Farhad
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Textile-Friendly Interconnection between Wearable Measurement Instrumentation and Sensorized Garments—Initial Performance Evaluation for Electrocardiogram Recordings2019Ingår i: Sensors, E-ISSN 1424-8220, Vol. 19, nr 29, s. 4426-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The interconnection between hard electronics and soft textiles remains a noteworthy challenge in regard to the mass production of textile–electronic integrated products such as sensorized garments. The current solutions for this challenge usually have problems with size, flexibility, cost, or complexity of assembly. In this paper, we present a solution with a stretchable and conductive carbon nanotube (CNT)-based paste for screen printing on a textile substrate to produce interconnectors between electronic instrumentation and a sensorized garment. The prototype connectors were evaluated via electrocardiogram (ECG) recordings using a sensorized textile with integrated textile electrodes. The ECG recordings obtained using the connectors were evaluated for signal quality and heart rate detection performance in comparison to ECG recordings obtained with standard pre-gelled Ag/AgCl electrodes and direct cable connection to the ECG amplifier. The results suggest that the ECG recordings obtained with the CNT paste connector are of equivalent quality to those recorded using a silver paste connector or a direct cable and are suitable for the purpose of heart rate detection.

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  • 24.
    Malm, Veronica
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Nierstrasz, Vincent
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Electrical resistance characterisations and durability of textile coatings containing metal flake fillers2018Konferensbidrag (Refereegranskat)
  • 25.
    Fernandez-Llatas, Carlos
    et al.
    ITACA-SABIEN, Universitat Politecnica de Valencia, Spain.
    Ibanez-Sanchez, Gema
    ITACA-SABIEN, Universitat Politecnica de Valencia, Spain.
    Traver, Vicente
    ITACA-SABIEN, Universitat Politecnica de Valencia, Spain.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Department of Biomedical Engineering, Karolinska University Hospital, Stockholm, Sweden; Department for Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
    Empowering ergonomy in workplaces by individual behavior modeling using interactive process mining paradigm2018Ingår i: Intelligent Environments 2018 / [ed] Ioannis Chatzigiannakis, Yoshito Tobe, Paulo Novais, Oliver Amft, Amsterdam: IOS Press, 2018, s. 346-354Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Work-related disorders account for a significant part of total healthcareexpenditure. Traditionally muscle-skeletal disorders were predominant as source ofwork absenteeism but in last years work activity-related disorders have increasedremarkably. Too little activity at work, sedentarism, or too much work activity leadsto stress. The individualized behavioural analysis of patients could support ergon-omy experts in the optimization of workplaces in a Healthier way. Process MiningTechnologies can offer a human understandable view of what is actually occurringin workplaces in an individualized way. In this paper, we present a proof of con-cept of how Process Mining technologies can be used for discovering the workerflow in order to support the ergonomy experts in the selection of more accurateinterventions for improving occupational health.

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  • 26.
    Malm, Veronica
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Nierstrasz, Vincent
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Fused deposition modelling – Towards 3D printed electrodes on fabric for surface electromyography (sEMG)2018Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Surface electromyography (sEMG) monitoring has promising applications within the field of human robot communication where wearable electrodes are used as the interface. This research investigates the production of flexible 3D printed electrodes using electrically conductive filaments, of thermoplastic polyurethane containing carbon black, and polyester fabric as substrate. Dry 3D printed electrodes of varying thickness, due to increased number of layers, were compared to conventional electrolytic gel electrodes. Initial tests show that the volume resistivity of 3D printed electrodes increased with increased number of layers. This because, with increased number of layers the diffusion between layers deteriorates and hinders conductive particle connections. Additional heat-treatments using hot press plates to improve diffusion between layers were promising as volume resistivity decreased with 200 % for all samples. As a first step to evaluate the 3D printed electrodes, skin-electrode impedance measurements were performed, and compared with measurements of conventional electrodes. Results showed that resistance and reactance versus frequency curves had similar trending slopes, decreasing with increasing frequency. However, this corresponded only between the thinnest (200 μm) 3D-printed dry electrode having a volume resistivity of 6.2 Ω cm and the conventional gel electrode. Future studies regarding the influence of platform and extruder temperature are planned for, focusing on improved diffusion between layers and increased conduction for proper electron transfer. 

  • 27.
    Abtahi, Farhad
    et al.
    Institute of Environmental Medicine, Karolinska Institutet, 171 65 Stockholm, Sweden; School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Lu, Ke
    School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Diaz-Olivares, Jose A
    School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Forsman, Mikael
    Institute of Environmental Medicine, Karolinska Institutet, 171 65 Stockholm, Sweden.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Hälsovägen 7, 141 57 Stockholm, Sweden; Department of Biomedical Engineering, Karolinska University Hospital, 171 76 Solna, Sweden .
    Lindecrantz, Kaj
    Högskolan i Borås, Science Park Borås. Institute of Environmental Medicine, Karolinska Institutet, 171 65 Stockholm, Sweden .
    Wearable Sensors Enabling Personalized Occupational Healthcare2018Ingår i: Intelligent Environments 2018 / [ed] Ioannis Chatzigiannakis, Yoshito Tobe, Paulo Novais, Oliver Amft, Amsterdam: IOS Press, 2018, s. 371-376Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    This paper presents needs and potentials for wearable sensors inoccupational healthcare. In addition, it presents ongoing European and Swedishprojects for developing personalized, and pervasive wearable systems for assessingrisks of developing musculoskeletal disorders and cardiovascular diseases at work.Occupational healthcare should benefit in preventing diseases and disorders byproviding the right feedback at the right time to the right person. Collected datafrom workers can provide evidence supporting the ergonomic and industrial tasksof redesigning the working environment to reduce the risks.

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  • 28.
    Vega-Barbas, Mario
    et al.
    Institute of Environmental Medicine, Karolinska Institutet, 171 65 Stockholm, Sweden.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. CLINTEC, Karolinska Institutet, Hälsovägen 7, 141 57 Stockholm, Sweden; Department of Biomedical Engineering, Karolinska University Hospital, 171 76 Solna, Sweden .
    Workshop on Personalized Health and Intelligent Workplaces Transforming Ergonomics2018Ingår i: Intelligent Environments 2018 / [ed] Ioannis Chatzigiannakis, Yoshito Tobe, Paulo Novais, Oliver Amft, IOS Press, 2018, s. 345-345Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 29.
    Abtahi, Farhad
    et al.
    Karolinska Institutet.
    Anund, Anna
    Fors, Carina
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Karolinska Institutet.
    Lindecrantz, Kaj
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Karolinska Institutet.
    Association of Drivers’ sleepiness with heart rate variability. A Pilot Study with Drivers on Real Road2017Konferensbidrag (Övrigt vetenskapligt)
  • 30.
    Jiong, Sun
    et al.
    Högskolan i Skövde.
    Billing, Erik
    Högskolan i Skövde.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Karolinska Institutet.
    Zhou, Bo
    DFKI.
    Högberg, Dan
    Högskolan i Skövde.
    Hemeren, Paul
    Högskolan i Skövde.
    Categories of touch: Classifying human touch using a soft tactile sensor2017Ingår i: The robotic sense of touch: From sensing to understanding, workshop at the IEEE International Conference on Robotics and Automation (ICRA), 29 May, Singapore., 2017Konferensbidrag (Refereegranskat)
  • 31.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Karolinska Institutet.
    Atefi, Seyed Reza
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Harvard Univsersity.
    Electrical bioimpedance enabling prompt intervention in traumatic brain injury2017Ingår i: SPIE Micro-and Nanotechnology Sensors, Systems, and Applications IX, 2017Konferensbidrag (Refereegranskat)
  • 32.
    Hafid, Abdelakram
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. University of Sciences and Technology Houari Boumediene.
    Benouar, Sara
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Kedir-Talha, Malika
    University of Sciences and Technology Houari Boumediene.
    Abtahi, Farhad
    Karolinska Institutet.
    Attari, Mokhtar
    University of Sciences and Technology Houari Boumediene.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Full Impedance Cardiography measurement device using Raspberry PI3 and System-on-Chip biomedical Instrumentation Solutions2017Ingår i: IEEE journal of biomedical and health informatics, ISSN 2168-2194, E-ISSN 2168-2208Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Impedance Cardiography (ICG) is a non-invasive method for monitoring cardiac dynamics using Electrical Bioimpedance (EBI) measurements. Since its appearance more than 40 years ago, ICG has been used for assessing hemodynamic parameters. This paper present a measurement system based on two System on Chip (SoC) solutions and Raspberry PI, implementing both a full 3-lead ECG recorder and an impedance cardiographer, for educational and research development purposes. Raspberry PI is a platform supporting Do-It-Yourself project and education applications across the world. The development is part of Biosignal PI, an open hardware platform focusing in quick prototyping of physiological measurement instrumentation. The SoC used for sensing cardiac biopotential is the ADAS1000, and for the EBI measurement is the AD5933. The recording were wirelessly transmitted through Bluetooth to a PC, where the waveforms were displayed, and hemodynamic parameters such as heart rate, stroke volume, ejection time and cardiac output were extracted from the ICG and ECG recordings. These results show how Raspberry PI can be used for quick prototyping using relatively widely available and affordable components, for supporting developers in research and engineering education. The design and development documents, will be available on www.BiosignalPI.com, for open access under a Non Commercial-Share A like 4.0 International License.

  • 33.
    Vega-Barbas, Mario
    et al.
    Royal Institute of Technology.
    Pau, Iván
    Universidad Politecnica de Madrid.
    Augusto, Juan C
    Middlesex University.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Karolinska Institutet.
    Interaction patterns for smart spaces. A confident interaction design solution for pervasive sensitive IoT services2017Ingår i: IEEE Access, E-ISSN 2169-3536Artikel i tidskrift (Refereegranskat)
  • 34.
    Cheng, Jingyuan
    et al.
    German Research Center for Artificial Intelligence (DFKI).
    Zhou, Bo
    German Research Center for Artificial Intelligence (DFKI).
    Lukowicz, Paul
    German Research Center for Artificial Intelligence (DFKI).
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Karolinska Institutet.
    Varga, Matija
    ETH Zurich.
    Mehmann, Andreas
    ETH Zurich.
    Chabrecek, Peter
    SEFAR AG.
    Gaschler, Werner
    SEFAR AG.
    Goenner, Karl
    ITV Denkendorf.
    Horter, Hansjürgen
    ITV Denkendorf.
    Schneegass, Stefan
    Hassib, Mariam
    University of Stuttgart.
    Schmidt, Albrecht
    University of Stuttgart.
    Freund, Martin
    University of Passau.
    Zhang, Rui
    University of Passau.
    Amft, Oliver
    University of Passau.
    Textile Building Blocks:Toward Simple, Modularized, and Standardized Smart Textile2017Ingår i: Smart Textiles: Fundamentals, Design, and Interaction, Springer, Cham , 2017, s. 303-331Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Textiles are pervasive in our life, covering human body and objects, as well as serving in industrial applications. In its everyday use of individuals, smart textile becomes a promising medium for monitoring, information retrieval, and interaction. While there are many applications in sport, health care, and industry, the state-of-the-art smart textile is still found only in niche markets. To gain mass-market capabilities, we see the necessity of generalizing and modularizing smart textile production and application development, which on the one end lowers the production cost and on the other end enables easy deployment. In this chapter, we demonstrate our initial effort in modularization. By devising types of universal sensing fabrics for conductive and non-conductive patches, smart textile construction from basic, reusable components can be made. Using the fabric blocks, we present four types of sensing modalities, including resistive pressure, capacitive, bioimpedance, and biopotential. In addition, we present a multi-channel textile–electronics interface and various applications built on the top of the basic building blocks by ‘cut and sew’ principle.

  • 35.
    Zhou, Bo
    et al.
    DFKI.
    Altamirano, Carlos Andres Velez
    DFKI.
    Zurian, Heber Cruz
    DFKI.
    Atefi, Seyed Reza
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Billing, Erik
    Högskolan i Skövde.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Lukowicz, Paul
    DFKI.
    Textile Pressure Mapping Sensor for Emotional Touch Detection in Human-Robot Interaction2017Ingår i: Sensors, Vol. 17, nr 11Artikel i tidskrift (Refereegranskat)
  • 36.
    Zhou, Bo
    et al.
    DFKI.
    Cruz, Heber Zurian
    DFKI.
    Atefi, Seyed Reza
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Harvard University.
    Billing, Erik
    Högskolan i Skövde.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. Karolinska Institutet.
    Lukowicz, Paul
    DFKI.
    TouchMe: Full-textile Touch Sensitive Skin for Encouraging Human-Robot Interaction2017Ingår i: The robotic sense of touch: from sensing to understanding, workshop at the IEEE International Conference on Robotics and Automation (ICRA), May 29-June 3, Singapore, 2017Konferensbidrag (Refereegranskat)
  • 37.
    Zhang, Rui
    et al.
    University of Passau.
    Freund, Martin
    University of Passau.
    Amft, Oliver
    University of Passau.
    Cheng, Jingyuan
    DFKI.
    Zhou, Bo
    DFKI.
    Lukowicz, Paul
    DFKI.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. KTH-School of Technology and Health.
    Chabrecek, Peter
    Sefar AG.
    A Generic Sensor Fabric for Multi-modal Swallowing Sensing in Regular Upper-body Shirts2016Ingår i: Proceedings of the 2016 ACM International Symposium on Wearable Computers, HEIDELBERG: ACM Digital Library , 2016, s. 46-47Konferensbidrag (Refereegranskat)
    Abstract [en]

    We investigate a generic fabric material as basis for resistive pressure and bio-impedance sensors and apply the fabric in a shirt collar for swallowing spotting. A pilot study confirmed the signal performance of both sensor types.

  • 38.
    Ferreira, Javier
    et al.
    KTH, Medicinsk teknik.
    Pau, Iván
    Universidad Politecnica de Madrid.
    Lindecrantz, Kaj
    KTH, Medicinsk teknik.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. KTH-School of Technology and Health.
    A handheld and textile-enabled bioimpedance system for ubiquitous body composition analysis.: An initial functional validation2016Ingår i: IEEE journal of biomedical and health informatics, ISSN 2168-2194, E-ISSN 2168-2208, nr 99Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In recent years, many efforts have been made to promote a healthcare paradigm shift from the traditional reactive hospital-centered healthcare approach towards a proactive, patient-oriented and self-managed approach that could improve service quality and help reduce costs while contributing to sustainability. Managing and caring for patients with chronic diseases accounts over 75% of healthcare costs in developed countries. One of the most resource demanding diseases is chronic kidney disease (CKD), which often leads to a gradual and irreparable loss of renal function, with up to 12% of the population showing signs of different stages of this disease. Peritoneal dialysis and home haemodialysis are life-saving home-based renal replacement treatments that, compared to conventional in-center hemodialysis, provide similar long-term patient survival, less restrictions of life-style, such as a more flexible diet, and better flexibility in terms of treatment options and locations. Bioimpedance has been largely used clinically for decades in nutrition for assessing body fluid distributions. Moreover, bioimpedance methods are used to assess the overhydratation state of CKD patients, allowing clinicians to estimate the amount of fluid that should be removed by ultrafiltration. In this work, the initial validation of a handheld bioimpedance system for the assessment of body fluid status that could be used to assist the patient in home-based CKD treatments is presented. The body fluid monitoring system comprises a custom-made handheld tetrapolar bioimpedance spectrometer and a textile-based electrode garment for total body fluid assessment. The system performance was evaluated against the same measurements acquired using a commercial bioimpedance spectrometer for medical use on several voluntary subjects. The analysis of the measurement results and the comparison of the fluid estimations indicated that both devices are equivalent from a measurement performance perspective, allowing for its use on ubiquitous e-healthcare dialysis solutions.

  • 39.
    Ayllon, David
    et al.
    Universidad de Alcalá.
    Gil-Pita, Roberto
    Universidad de Alcalá.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. KTH-School of Technology and Health.
    Detection and Classification of Measurement Errors in Bioimpedance Spectroscopy2016Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 11, nr 6, artikel-id e0156522Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bioimpedance spectroscopy (BIS) measurement errors may be caused by parasitic stray capacitance, impedance mismatch, cross-talking or their very likely combination. An accurate detection and identification is of extreme importance for further analysis because in some cases and for some applications, certain measurement artifacts can be corrected, minimized or even avoided. In this paper we present a robust method to detect the presence of measurement artifacts and identify what kind of measurement error is present in BIS measurements. The method is based on supervised machine learning and uses a novel set of generalist features for measurement characterization in different immittance planes. Experimental validation has been carried out using a database of complex spectra BIS measurements obtained from different BIS applications and containing six different types of errors, as well as error-free measurements. The method obtained a low classification error (0.33%) and has shown good generalization. Since both the features and the classification schema are relatively simple, the implementation of this pre-processing task in the current hardware of bioimpedance spectrometers is possible.

  • 40. Brown, Shannon
    et al.
    Ortiz-Catalan, Max
    Chalmers University of Technology.
    Petersson, Joel
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. KTH-School of Technology and Health.
    Intarsia-sensorized band and textrodes for real-time myoelectric pattern recognition2016Ingår i: Engineering in Medicine and Biology Society (EMBC), 2016 IEEE 38th Annual International Conference of the, Institute of Electrical and Electronics Engineers (IEEE) , 2016, s. 6074-6077Konferensbidrag (Refereegranskat)
    Abstract [en]

    Surface Electromyography (sEMG) has applications in prosthetics, diagnostics and neuromuscular rehabilitation. Self-adhesive Ag/AgCl are the electrodes preferentially used to capture sEMG in short-term studies, however their long-term application is limited. In this study we designed and evaluated a fully integrated smart textile band with electrical connecting tracks knitted with intarsia techniques and knitted textile electrodes. Real-time myoelectric pattern recognition for motor volition and signal-to-noise ratio (SNR) were used to compare its sensing performance versus the conventional Ag-AgCl electrodes. After a comprehending measurement and performance comparison of the sEMG recordings, no significant differences were found between the textile and the Ag-AgCl electrodes in SNR and prediction accuracy obtained from pattern recognition classifiers.

  • 41. Brown, Shannon
    et al.
    Ortiz-Catalan, Max
    Chalmers University of Technology.
    Petersson, Joel
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. Högskolan i Borås.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. KTH-School of Technology and Health.
    Intarsia-Sensorized Band and Textrodes for the Acquisition of Myoelectric Signals2016Ingår i: The Second International Conference on Smart Portable, Wearable, Implantable and Disability-oriented Devices and Systems, International Academy, Research and Industry Association (IARIA) , 2016, s. 14-19, artikel-id 2_10_80013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Surface Electromyography (sEMG) has applications in prosthetics, diagnostics and neuromuscular rehabilitation, and has been an increasing area of study. This study attempts to use a fully integrated smart textile band with electrical connecting tracks knitted with intarsia techniques to evaluate the quality of sEMG acquired by knitted textile electrodes. Myoelectric pattern recognition for motor volition and signal-to-noise ratio (SNR) were used to compare its sensing performance versus the conventional Ag-AgCl electrodes. Overall no significant differences were found between the textile and the Ag-AgCl electrodes in SNR and prediction accuracy obtained from pattern recognition classifiers. On average the textile electrodes produced a high prediction accuracy, >97% across all movements, which is equivalent to the accuracy obtained with conventional gel electrodes (Ag-AgCl). Furthermore the SNR for the Maximum Voluntary Contraction did not differ considerably between the textile and the Ag-AgCl electrodes.

  • 42.
    Atefi, Seyed Reza
    et al.
    Harvard Univsersity.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Kamalian, Shervin
    Rosenthal, Eric
    Lev, Michael
    Massachussets University Hospital.
    Bonmassar, Giorgio
    Harvard University.
    Intracranial haemorrhage alters scalp potential distributions in bioimpedance cerebral monitoring applications: preliminary results from FEM simulation on a realistic head model and human subjects2016Ingår i: Medical Physics, ISSN 0094-2405, Vol. 43, nr 2, s. 675-686Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose:

    Current diagnostic neuroimaging for detection of intracranial hemorrhage (ICH) is limited to fixed scanners requiring patient transport and extensive infrastructure support. ICH diagnosis would therefore benefit from a portable diagnostic technology, such as electrical bioimpedance (EBI). Through simulations and patient observation, the authors assessed the influence of unilateral ICH hematomas on quasisymmetric scalp potential distributions in order to establish the feasibility of EBI technology as a potential tool for early diagnosis.

    Methods:

    Finite element method(FEM) simulations and experimental left–right hemispheric scalp potential differences of healthy and damaged brains were compared with respect to the asymmetry caused by ICH lesions on quasisymmetric scalp potential distributions. In numerical simulations, this asymmetry was measured at 25 kHz and visualized on the scalp as the normalized potential difference between the healthy and ICH damaged models. Proof-of-concept simulations were extended in a pilot study of experimental scalp potential measurements recorded between 0 and 50 kHz with the authors’ custom-made bioimpedance spectrometer. Mean left–right scalp potential differences recorded from the frontal, central, and parietal brain regions of ten healthy control and six patients suffering from acute/subacute ICH were compared. The observed differences were measured at the 5% level of significance using the two-sample Welch t-test.

    Results:

    The 3D-anatomically accurate FEM simulations showed that the normalized scalp potential difference between the damaged and healthy brainmodels is zero everywhere on the head surface, except in the vicinity of the lesion, where it can vary up to 5%. The authors’ preliminary experimental results also confirmed that the left–right scalp potential difference in patients with ICH (e.g., 64 mV) is significantly larger than in healthy subjects (e.g., 20.8 mV; P < 0.05).

    Conclusions:

    Realistic, proof-of-concept simulations confirmed that ICH affects quasisymmetric scalp potential distributions. Pilot clinical observations with the authors’ custom-made bioimpedance spectrometer also showed higher left–right potential differences in the presence of ICH, similar to those of their simulations, that may help to distinguish healthy subjects from ICH patients. Although these pilot clinical observations are in agreement with the computer simulations, the small sample size of this study lacks statistical power to exclude the influence of other possible confounders such as age, sex, and electrode positioning. The agreement with previously published simulation-based and clinical results, however, suggests that EBI technology may be potentially useful for ICH detection.

  • 43.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Soroudi, Azadeh
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Abtahi, Farhad
    KTH, Medicinsk teknik.
    Lu, Ke
    KTH-School of Technology and Health.
    Skrifvars, Mikael
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Printed Electronics Enabling a Textile-friendly Interconnection between Wearable Measurement Instrumentation & Sensorized Garments2016Konferensbidrag (Refereegranskat)
  • 44.
    Wollmann, Thomas
    et al.
    GECKO Institute, Heilbronn University, Heilbronn, Germany.
    Abtahi, Farhad
    KTH-School of Technology and Health.
    Eghdam, Abouzar
    Department of Learning, Informatics, Management and Ethics, Health Informatics Centre, Karolinska Institute.
    Seoane, Fernando
    Högskolan i Borås, Akademin för textil, teknik och ekonomi. KTH-School of Technology and Health.
    Lindecrantz, Kaj
    KTH-School of Technology and Health.
    Haag, Martin
    GECKO Institute, Heilbronn University, Heilbronn, Germany.
    Koch, Sabine
    Department of Learning, Informatics, Management and Ethics, Health Informatics Centre, Karolinska Institute.
    User-Centred Design and Usability Evaluation of a Heart Rate Variability Biofeedback Game2016Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. PP, nr 99, s. 1-1Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background and objective: Reduced heart rate variability (HRV) is an indicatorof a malfunctioning autonomic nervous system. Resonant frequencybreathing is a potential non-invasive means of intervention for improvingthe balance of the autonomic nervous system and increasing HRV. However,such breathing exercises are regarded as boring and monotonous tasks.The use of gaming elements (gamification) or a full gaming experience is awell-recognised method for achieving higher motivation and engagement invarious tasks. However, there is limited documented knowledge on how todesign a game for breathing exercises. In particular, the influence of additionalinteractive elements on the main course of training has not yet beenexplored. In this study, we evaluated the satisfaction levels achieved usingdifferent game elements and how disruptive they were to the main task, i.e.,paced breathing training.

    Methods: An Android flight game was developed with three game modes thatdiffer in the degrees of multitasking they require. Design, development and evaluation were conducted using a user-centred approach, including contextanalysis, the design of game principle mock-ups, the selection of game principlesthrough a survey, the design of the game mechanics and GUI mock-up,icon testing and the performance of a summative study through user questionnairesand interviews. A summative evaluation of the developed gamewas performed with 11 healthy participants (ages 40-67) in a controlled setting.Results: The results confirm the potential of video games for motivatingplayers to engage in HRV biofeedback training. The highest training performanceon the first try was achieved through pure visualisation rather thanin a multitasking mode. Players had higher motivation to play the morechallenging game and were more interested in long-term engagement.Conclusion: A framework for gamified HRV biofeedback research is presented.It has been shown that multitasking has considerable influence onHRV biofeedback and should be used with an adaptive challenge level.

  • 45.
    Abtahi, Farhad
    et al.
    KTH-School of Technology and Health.
    Lu, Ke
    KTH-School of Technology and Health.
    Guangchao, Li
    KTH-School of Technology and Health.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    A Knitted Garment using Intarsia Technique for Heart Rate Variability Biofeedback: Evaluation of Initial Prototype.2015Konferensbidrag (Övrigt vetenskapligt)
  • 46.
    Abtahi, Farhad
    et al.
    KTH-School of Technology and Health.
    Ji, Guangchao
    KTH-School of Technology and Health.
    Lu, Ke
    KTH-School of Technology and Health.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    A knitted garment using intarsia technique for Heart Rate Variability biofeedback: Evaluation of initial prototype2015Ingår i: Proceedings of the 2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2015, s. 3121-3124Konferensbidrag (Refereegranskat)
  • 47.
    Vega-Barbas, Mario
    et al.
    KTH-School of Technology and Health.
    Pau, Iván
    Universidad Politecnica de Madrid.
    Martín-Ruiz, María Luisa
    Universidad Politecnica de Madrid.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Adaptive Software Architecture Based on Confident HCI for the Deployment of Sensitive Services in Smart Homes2015Ingår i: Sensors, E-ISSN 1424-8220, Vol. 15, nr 4, s. 7294-7322Artikel i tidskrift (Refereegranskat)
  • 48.
    Mohino-Herranz, Inma
    et al.
    University of Alcala.
    Gil-Pita, Roberto
    University of Alcala.
    Ferreira, Javier
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Rosa-Zurera, Manuel
    University of Alcala.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Assessment of Mental, Emotional and Physical Stress through Analysis of Physiological Signals Using Smartphones2015Ingår i: Sensors, E-ISSN 1424-8220, Vol. 15, nr 10, s. 25607-25627Artikel i tidskrift (Refereegranskat)
  • 49. Abtahi, Farhad
    et al.
    Snäll, Jonathan
    Aslamy, Benjamin
    Abtahi, Shirin
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Lindecrantz, Kaj
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Biosignal PI, an Affordable Open-Source ECG and Respiration Measurement System2015Ingår i: Sensors, E-ISSN 1424-8220, Vol. 15, nr 1, s. 93-109Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bioimedical pilot projects e.g., telemedicine, homecare, animal and human trials usually involve several physiological measurements. Technical development of these projects is time consuming and in particular costly. A versatile but affordable biosignal measurement platform can help to reduce time and risk while keeping the focus on the important goal and making an efficient use of resources. In this work, an affordable and open source platform for development of physiological signals is proposed. As a first step an 8–12 leads electrocardiogram (ECG) and respiration monitoring system is developed. Chips based on iCoupler technology have been used to achieve electrical isolation as required by IEC 60601 for patient safety. The result shows the potential of this platform as a base for prototyping compact, affordable, and medically safe measurement systems. Further work involves both hardware and software development to develop modules. These modules may require development of front-ends for other biosignals or just collect data wirelessly from different devices e.g., blood pressure, weight, bioimpedance spectrum, blood glucose, e.g., through Bluetooth. All design and development documents, files and source codes will be available for non-commercial use through project website, BiosignalPI.org.

  • 50.
    Abtahi, Farhad
    et al.
    KTH-School of Technology and Health.
    Lu, Ke
    KTH-School of Technology and Health.
    Dizon, M
    KTH-School of Technology and Health.
    Johansson, M
    KTH-School of Technology and Health.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Lindecrantz, Kaj
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Evaluating Atrial Fibrillation Detection Algorithm based on Heart Rate Variability analysis2015Ingår i: Medicinteknikdagarna, Uppsala: Svensk förening för medicinsk teknik och fysik , 2015Konferensbidrag (Refereegranskat)
  • 51.
    Abtahi, Farhad
    et al.
    KTH-School of Technology and Health.
    Lu, Ke
    KTH-School of Technology and Health.
    Dizon, M
    KTH-School of Technology and Health.
    Johansson, M
    KTH-School of Technology and Health.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Lindecrantz, Kaj
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Evaluation of Atrial Fibrillation Detection by using Heart Rate Variability analysis2015Konferensbidrag (Övrigt vetenskapligt)
  • 52.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Abtahi, Shirin
    Karolinkska University Hospital.
    Abtahi, Farhad
    KTH-School of Technology and Health.
    Ellegård, Lars
    University of Gothenburg.
    Johannsson, Gudmundur
    University of Gothenburg.
    Bosaeus, Ingvar
    University of Gothenburg.
    Ward, Leigh C
    University of Queensland.
    Mean Expected Error in Prediction of Total Body Water.: A True Accuracy Comparison between Bioimpedance Spectroscopy and Single Frequency Regression Equations.2015Ingår i: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, Vol. 2015Artikel i tidskrift (Refereegranskat)
  • 53.
    Chen, Wei
    et al.
    Fudan University.
    Augusto, Juan CarlosMiddlesex University.Seoane, FernandoHögskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.Ledhocki, FedorSlovak University of Technology.Arends, JohanTechnical University of Technology.Ungureanu, ConstantinHobo Heeze.Wichert, ReinerFraunhofer IGD.
    Recent Advances in Ambient Assisted Living: Bridging Assistive Technologies, e-Health and Personalized Health Care2015Samlingsverk (redaktörskap) (Refereegranskat)
  • 54. Schneegass, Stefan
    et al.
    Hassib, Mariam
    Zhou, Bo
    Cheng, Jingyuan
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Amft, Oliver
    Lukowicz, Paul
    Schmidt, Albrecht
    SimpleSkin: towards multipurpose smart garments2015Ingår i: Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2015 ACM International Symposium on Wearable Computers, ACM Publications, 2015, s. 241-244Konferensbidrag (Refereegranskat)
  • 55.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Abtahi, Shirin
    Karolinska University Hospital.
    Abtahi, Farhad
    KTH-School of Technology and Health.
    Ellegård, Lars
    Sahlgrenska University Hospital.
    Johannsson, Gudmundur
    Sahlgrenska University Hospital.
    Bosaeus, Ingvar
    University of Gothenburg.
    Ward, Leigh
    University of Queensland.
    Slightly superior performance of bioimpedance spectroscopy over single frequency regression equations for assessment of total body water2015Konferensbidrag (Refereegranskat)
  • 56.
    Abtahi, Farhad
    et al.
    KTH-School of Technology and Health.
    Ji, Guangchao
    KTH-School of Technology and Health.
    Lu, Ke
    KTH-School of Technology and Health.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Björlin, Anders
    Kiwok AB.
    Östlund, Anders
    Kiwok AB.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Lindecrantz, Kaj
    KTH-School of Technology and Health.
    Textile-Electronic Integration in Wearable Measurement Garments for Pervasive Healthcare Monitoring2015Konferensbidrag (Övrigt vetenskapligt)
  • 57. Vega-Barbas, Mario
    et al.
    Pau, Ivan
    Valero, Miguel Angel
    Seoane, Fernando
    Högskolan i Borås, Institutionen för Vårdvetenskap.
    Adaptive Software Architecture for Confident Homecare in the Digital Home2014Konferensbidrag (Refereegranskat)
  • 58. Abtahi, Farhad
    et al.
    Aslamy, Benjamin
    Boujabir, I
    Seoane, Fernando
    Högskolan i Borås, Institutionen för Vårdvetenskap.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    An Affordable ECG and Respiration Monitoring System Based on Raspberry PI and ADAS1000: First Step towards Homecare Applications2014Ingår i: 16th Nordic-Baltic Conference on Biomedical Engineering / [ed] Mindedal H., Persson M., Springer International Publishing , 2014, s. 5-8Konferensbidrag (Refereegranskat)
    Abstract [en]

    Homecare is a potential solution for problems associated with an aging population. This may involve several physiological measurements, and hence a flexible but affordable measurement device is needed. In this work, we have designed an ADAS1000-based four-lead electrocardiogram (ECG) and respiration monitoring system. It has been implemented using Raspberry PI as a platform for homecare applications. ADuM chips based on iCoupler technology have been used to achieve electrical isolation as required by IEC 60601 and IEC 60950 for patient safety. The result proved the potential of Raspberry PI for the design of a compact, affordable, and medically safe measurement device. Further work involves developing a more flexible software for collecting measurements from different devices (measuring, e.g., blood pressure, weight, impedance spectroscopy, blood glucose) through Bluetooth or user input and integrating them into a cloud-based homecare system.

  • 59. Vega-Barbas, Mario
    et al.
    Pau, Ivan
    Seoane, Fernando
    Högskolan i Borås, Institutionen för Vårdvetenskap.
    Confidence: dependencies and their critical role in fostering user acceptance in pervasive applications2014Konferensbidrag (Refereegranskat)
    Abstract [en]

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

  • 60.
    Abtahi, Farhad
    et al.
    Högskolan i Borås, Institutionen för Vårdvetenskap.
    Berndtsson, A
    Högskolan i Borås, Institutionen för Vårdvetenskap.
    Abtahi, Shirin
    Högskolan i Borås, Institutionen för Vårdvetenskap.
    Seoane, Fernando
    Högskolan i Borås, Institutionen för Vårdvetenskap.
    Lindecrantz, Kaj
    KTH.
    Development and preliminary evaluation of an Android based heart rate variability biofeedback system2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    The reduced Heart Rate Variability (HRV) is believed to be associated with several diseases such as congestive heart failure, diabetes and chronic kidney diseases (CKD). In these cases, HRV biofeedback may be a potential intervention method to increase HRV which in turn is beneficial to these patients. In this work, a real-time Android biofeedback application based on a Bluetooth enabled ECG and thoracic electrical bioimpedance (respiration) measurement device has been developed. The system performance and usability have been evaluated in a brief study with eight healthy volunteers. The result demonstrates real-time performance of system and positive effects of biofeedback training session by increased HRV and reduced heart rate. Further development of the application and training protocol is ongoing to investigate duration of training session to find an optimum length and interval of biofeedback sessions to use in potential interventions.

  • 61. Abtahi, F
    et al.
    Seoane, F
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Lindecrantz, K
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Electrical bioimpedance spectroscopy in time-variant systems: Is undersampling always a problem?2014Ingår i: Journal of Electrical Bioimpedance, E-ISSN 1891-5469, Vol. 5, nr 1, s. 28-33Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During the last decades, Electrical Bioimpedance Spectroscopy (EBIS) has been applied mainly by using the frequency-sweep technique, across a range of many different applications. Traditionally, the tissue under study is considered to be time-invariant and dynamic changes of tissue activity are ignored by treating the changes as a noise source. A new trend in EBIS is simultaneous electrical stimulation with several frequencies, through the application of a multi-sine, rectangular or other waveform. This method can provide measurements fast enough to sample dynamic changes of different tissues, such as cardiac muscle. This high sampling rate comes at a price of reduction in SNR and the increase in complexity of devices. Although the frequency-sweep technique is often inadequate for monitoring the dynamic changes in a variant system, it can be used successfully in applications focused on the time-invariant or slowly-variant part of a system. However, in order to successfully use frequency-sweep EBIS for monitoring time-variant systems, it is paramount to consider the effects of aliasing and especially the folding of higher frequencies, on the desired frequency e.g. DC level. This paper discusses sub-Nyquist sampling of thoracic EBIS measurements and its application in the case of monitoring pulmonary oedema. It is concluded that by considering aliasing, and with proper implementation of smoothing filters, as well as by using random sampling, frequency-sweep EBIS can be used for assessing time-invariant or slowly-variant properties of time-variant biological systems, even in the presence of aliasing. In general, undersampling is not always a problem, but does always require proper consideration.

  • 62. Buendia, Ruben
    et al.
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Bosaeus, Ingvar
    Gil-Pita, Roberto
    Johannsson, G
    Ellegård, Lars
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Robustness study of the different immittance spectra and frequency ranges in bioimpedance spectroscopy analysis for assessment of total body composition2014Ingår i: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, ISSN 0967-3334, Vol. 35, nr 7, s. 1373-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The estimation of body fluids is a useful and common practice for assessment of disease status and therapy outcomes. Electrical bioimpedance spectroscopy (EBIS) methods are noninvasive, inexpensive and efficient alternatives for determination of body fluids. One of the main source of errors in EBIS measurements in the estimation of body fluids is capacitive coupling. In this paper an analysis of capacitive coupling in EBIS measurements was performed and the robustness of the different immittance spectra against it tested. On simulations the conductance (G) spectrum presented the smallest overall error, among all immittance spectra, in the estimation of the impedance parameters used to estimate body fluids. Afterwards the frequency range of 10–500 kHz showed to be the most robust band of the G spectrum. The accuracy of body fluid estimations from the resulting parameters that utilized G spectrum and parameters provided by the measuring device were tested on EBIS clinical measurements from growth hormone replacement therapy patients against estimations performed with dilution methods. Regarding extracellular fluid, the correlation between each EBIS method and dilution was 0.93 with limits of agreement of 1.06 ± 2.95 l for the device, 1.10 ± 2.94 l for G [10–500 kHz] and 1.04 ± 2.94 l for G [5–1000 kHz]. Regarding intracellular fluid, the correlation between dilution and the device was 0.91, same as for G [10–500 kHz] and 0.92 for G [5–1000 kHz]. Limits of agreement were 0.12 ± 4.46 l for the device, 0.09 ± 4.45 for G [10–500 kHz] and 0.04 ± 4.58 for G [5–1000 kHz]. Such close results between the EBIS methods validate the proposed approach of using G spectrum for initial Cole characterization and posterior clinical estimation of body fluids status.

  • 63. Atefi, Seyed Reza
    et al.
    Seoane, Fernando
    Högskolan i Borås, Institutionen för Vårdvetenskap.
    The Emergence of Electrical Bioimpedance Monitoring for Prompt Detection of Stroke Damage2014Konferensbidrag (Refereegranskat)
  • 64.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Mohino-Herranz, Inmaculada
    Ferreira González, Javier
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Alvarez, Lorena
    Buendia, Ruben
    Ayllón, David
    Cosme, Llerena
    Gil-Pita, Roberto
    Wearable Biomedical Measurement Systems for Assessment of Mental Stress of Combatants in Real Time2014Ingår i: Sensors, E-ISSN 1424-8220, Vol. 14, nr 4, s. 7120-7141Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Spanish Ministry of Defense, through its Future Combatant program, has sought to develop technology aids with the aim of extending combatants' operational capabilities. Within this framework the ATREC project funded by the “Coincidente” program aims at analyzing diverse biometrics to assess by real time monitoring the stress levels of combatants. This project combines multidisciplinary disciplines and fields, including wearable instrumentation, textile technology, signal processing, pattern recognition and psychological analysis of the obtained information. In this work the ATREC project is described, including the different execution phases, the wearable biomedical measurement systems, the experimental setup, the biomedical signal analysis and speech processing performed. The preliminary results obtained from the data analysis collected during the first phase of the project are presented, indicating the good classification performance exhibited when using features obtained from electrocardiographic recordings and electrical bioimpedance measurements from the thorax. These results suggest that cardiac and respiration activity offer better biomarkers for assessment of stress than speech, galvanic skin response or skin temperature when recorded with wearable biomedical measurement systems.

  • 65.
    Atefi, Seyed Reza
    et al.
    Harvard University.
    Seoane, Fernando
    Högskolan i Borås, Akademin för vård, arbetsliv och välfärd. KTH-School of Technology and Health.
    Thorlin, Thorleif
    salhgrenska Hospital.
    Lindecrantz, Kaj
    KTH-School of Technology and Health.
    Stroke Damage Detection Using Classification Trees on Electrical Bioimpedance Cerebral Spectroscopy Measurements2013Ingår i: Sensors, E-ISSN 1424-8220, Vol. 13, nr 8, s. 10074-10086Artikel i tidskrift (Refereegranskat)
  • 66.
    Márquez, Juan Carlos
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Textrode functional straps for bioimpedance measurements-experimental results for body composition analysis2013Ingår i: European Journal of Clinical Nutrition, ISSN 0954-3007, E-ISSN 1476-5640, Vol. 67, nr Suppl 1, s. 22-27Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background/Objectives:Functional garments for physiological sensing purposes have been used in several disciplines, that is, sports, firefighting, military and medicine. In most of the cases, textile electrodes (textrodes) embedded in the garment are used to monitor vital signs and other physiological measurements. Electrical bioimpedance (EBI) is a non-invasive and effective technology that can be used for the detection and supervision of different health conditions.EBI technology could make use of the advantages of garment integration; however, a successful implementation of EBI technology depends on the good performance of textrodes. The main drawback of textrodes is a deficient skin-electrode interface that produces a high degree of sensitivity to signal disturbances. This sensitivity can be reduced with a suitable selection of the electrode material and an intelligent and ergonomic garment design that ensures an effective skin-electrode contact area.Subjects/Methods:In this work, textrode functional straps for total right side EBI measurements for body composition are presented, and its measurement performance is compared against the use of Ag/AgCl electrodes. Shieldex sensor fabric and a tetra-polar electrode configuration using the ImpediMed spectrometer SFB7 in the frequency range of 3-500 kHz were used to obtain and analyse the impedance spectra and Cole and body composition parameters.Results:The results obtained show stable and reliable measurements; the slight differences obtained with the functional garment do not significantly affect the computation of Cole and body composition parameters.Conclusions:The use of a larger sensor area, a high conductive material and an appropriate design can compensate, to some degree, for the charge transfer deficiency of the skin-electrode interface.

  • 67.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Ferreira, Javier
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Buendia, Ruben
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Adaptive Frequency Distribution for Electrical Bioimpedance Spectroscopy Measurements2012Konferensbidrag (Refereegranskat)
    Abstract [en]

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

  • 68.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Ward, L. C.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Lingwood, B. E.
    Automated criterion-based analysis for Cole parameters assessment from cerebral neonatal electrical bioimpedance spectroscopy measurements2012Ingår i: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, Vol. 33, nr 8, s. 1363-1377Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hypothermia has been proven as an effective rescue therapy for infants with moderate or severe neonatal hypoxic ischemic encephalopathy. Hypoxia-ischemia alters the electrical impedance characteristics of the brain in neonates; therefore, spectroscopic analysis of the cerebral bioimpedance of the neonate may be useful for the detection of candidate neonates eligible for hypothermia treatment. Currently, in addition to the lack of reference bioimpedance data obtained from healthy neonates, there is no standardized approach established for bioimpedance spectroscopy data analysis. In this work, cerebral bioimpedance measurements (12 h postpartum) in a cross-section of 84 term and near-term healthy neonates were performed at the bedside in the post-natal ward. To characterize the impedance spectra, Cole parameters (R(0), R(∞), f(C) and α) were extracted from the obtained measurements using an analysis process based on a best measurement and highest likelihood selection process. The results obtained in this study complement previously reported work and provide a standardized criterion-based method for data analysis. The availability of electrical bioimpedance spectroscopy reference data and the automatic criterion-based analysis method might support the development of a non-invasive method for prompt selection of neonates eligible for cerebral hypothermic rescue therapy.

  • 69. Reza Atefi, Seyed
    et al.
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Buendia, Ruben
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Cole Function and Conductance-Based Parasitic Capacitance Compensation for Cerebral Electrical Bioimpedance Measurements2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    One of the most common measurement artifacts present in Electrical Bioimpedance Spectroscopy measurements (EBIS) comes from the capacitive leakage effect resulting from parasitic stray capacitances. This artifact produces a deviation in the measured impedance spectrum that is most noticeable at higher frequencies. The artifact taints the spectroscopy measurement increasing the difficulty of producing reliable EBIS measurements at high frequencies. In this work, an approach for removing such capacitive influence from the spectral measurement is presented making use of a novel method to estimate the value of the parasitic capacitance equivalent that causes the measurement artifact. The proposed method has been tested and validated theoretically and experimentally and it gives a more accurate estimation of the value of the parasitic capacitance than the previous methods. Once a reliable value of parasitic capacitance has been estimated the capacitive influence can be easily compensated in the EBIS measured data. Thus enabling analysis of EBIS data at higher frequencies, i.e. in the range of 300-500 kHz like measurements intended for cerebral monitoring, where the characteristic frequency is remarkably higher than EBIS measurements i.e. within the range 30 to 50 kHz, intended for body composition assessment.

  • 70. Atefi, S. R.
    et al.
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Electrical Bioimpedance Cerebral Monitoring.: Preliminary Results from Measurements on Stroke Patients2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Electrical Bioimpedance Spectroscopy (EBIS) is currently used in different tissue characterization applications. In this work we aim to use EBIS to study changes in electrical properties of the cerebral tissues after an incident of hemorrhage/ischemic stroke. To do so a case-control study was conducted using six controls and three stroke cases. The preliminary results of this study show that by using Cole-based analysis on EBIS measurements and analyzing the Cole parameters R0 and R∞, it is possible to detect changes on electrical properties of cerebral tissue after stroke.

  • 71.
    Buendía, Rubén
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Bogónez-Franco, Paco
    Nescolarde, Lexa
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Influence of electrode mismatch on Cole parameter estimation from Total Right Side Electrical Bioimpedance Spectroscopy measurements2012Ingår i: Medical Engineering and Physics, ISSN 1350-4533, E-ISSN 1873-4030, Vol. 34, nr 7, s. 1024-1028Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Applications based on measurements of Electrical Bioimpedance (EBI) spectroscopy analysis, like assessment of body composition, have proliferated in the past years. Currently Body Composition Assessment (BCA) based in Bioimpedance Spectroscopy (BIS) analysis relays on an accurate estimation of the Cole parameters R0 and R∞. A recent study by Bogonez-Franco et al. has proposed electrode mismatch as source of remarkable artefacts in BIS measurements. Using Total Right Side BIS measurements from the aforementioned study, this work has focused on the influence of electrode mismatch on the estimation of R0 and R∞ using the Non-Linear Least Square curve fitting technique on the modulus of the impedance. The results show that electrode mismatch on the voltage sensing electrodes produces an overestimation of the impedance spectrum leading to a wrong estimation of the parameters R0 and R∞, and consequently obtaining values around 4% larger that the values obtained from BIS without electrode mismatch. The specific key factors behind electrode mismatch or its influence on the analysis of single and spectroscopy measurements have not been investigated yet, no compensation or correction technique is available to overcome the deviation produced on the EBI measurement. Since textile-enabled EBI applications using dry textrodes, i.e. textile electrodes with dry skin–electrode interfaces and potentially large values of electrode polarization impedance are more prone to produce electrode mismatch, the lack of a correction or compensation technique might hinder the proliferation of textile-enabled EBI applications for personalized healthcare monitoring.

  • 72. Abtahi, F.
    et al.
    Gyllesten, I. C.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Software Tool for Analysis of Breathing Related Errors in Transthoracic Electrical Bioimpedance Spectroscopy Measurements2012Konferensbidrag (Refereegranskat)
  • 73.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Gawel, J
    Ferreira, J.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Wirstrand, J.
    Stretchable Circuit Board Technology enabling Seamless Textile-Electronic Integration for Electrical Muscle Stimulation Therapy2012Konferensbidrag (Refereegranskat)
  • 74. Löfhede, J.
    et al.
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Thordstein, M.
    Textile Electrodes for EEG Recording: A Pilot Study2012Ingår i: Sensors, E-ISSN 1424-8220, Vol. 12, nr 12, s. 16907-16919Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Abstract: The overall aim of our research is to develop a monitoring system for neonatal intensive care units. Long-term EEG monitoring in newborns require that the electrodes don’t harm the sensitive skin of the baby, an especially relevant feature for premature babies. Our approach to EEG monitoring is based on several electrodes distributed over the head of the baby, and since the weight of the head always will be on some of them, any type of hard electrode will inevitably cause a pressure-point that can irritate the skin. Therefore, we propose the use of soft conductive textiles as EEG electrodes, primarily for neonates, but also for other kinds of unobtrusive long-term monitoring. In this paper we have tested two types of textile electrodes on five healthy adults and compared them to standard high quality electrodes. The acquired signals were compared with respect to morphology, frequency distribution, spectral coherence, correlation and power line interference sensitivity, and the signals were found to be similar in most respects. The good measurement performance exhibited by the textile electrodes indicates that they are feasible candidates for EEG recording, opening the door for long-term EEG monitoring applications.

  • 75.
    Ferreira Gonzalez, Javier
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    AD5933-Based Electrical Bioimpedance Spectrometer. Towards Textile-Enabled Applications.2011Konferensbidrag (Refereegranskat)
  • 76.
    Buendia, Ruben
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Gil-Pita, Roberto
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Cole Parameter Estimation from the Modulus of the Electrical Bioimpeadance for Assessment of Body Composition. A Full Spectroscopy Approach2011Ingår i: Journal of Electrical Bioimpedance, E-ISSN 1891-5469, Vol. 2, s. 72-78Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Activities around applications of Electrical Bioimpedance Spectroscopy (EBIS) have proliferated in the past decade significantly. Most of these activities have been focused in the analysis of the EBIS measurements, which eventually might enable novel applications. In Body Composition Assessment (BCA), the most common analysis approach currently used in EBIS is based on the Cole function, which most often requires curve fitting. One of the most implemented approaches for obtaining the Cole parameters is performed in the impedance plane through the geometrical properties that the Cole function exhibit in such domain as depressed semi-circle. To fit the measured impedance data to a semi-circle in the impedance plane, obtaining the Cole parameters in an indirect and sequential manner has several drawbacks. Applying a Non-Linear Least Square (NLLS) iterative fitting on the spectroscopy measurement, obtains the Cole parameters considering the frequency information contained in the measurement. In this work, from experimental total right side EBIS measurements, the BCA parameters have been obtained to assess the amount and distribution of whole body fluids. The values for the BCA parameters have been obtained using values for the Cole parameters estimated with both approaches: circular fitting on the impedance plane and NLLS impedance-only fitting. The comparison of the values obtained for the BCA parameters with both methods confirms that the NLLS impedance-only is an effective alternative as Cole parameter estimation method in BCA from EBIS measurements. Using the modulus of the Cole function as the model for the fitting would eliminate the need for performing phase detection in the acquisition process, simplifying the hardware specifications of the measurement instrumentation when implementing a bioimpedance spectrometer.

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  • 77.
    Buendia, Ruben
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Gil-Pita, Roberto
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Cole parameter estimation from total right side electrical bioimpedance spectroscopy measurements: Influence of the number of frequencies and the upper limit2011Ingår i: Engineering in Medicine and Biology Society,EMBC, 2011 Annual International Conference of the IEEE, IEEE , 2011, s. 1843-1846Konferensbidrag (Refereegranskat)
    Abstract [en]

    Applications based on measurements of Electrical Bioimpedance Spectrocopy (EBIS) analysis are proliferating. The most spread and known application of EBIS is the non-invasive assessment of body composition. Fitting to the Cole function to obtain the Cole parameters, R0 and R∞, is the core of the EBIS analysis to obtain the body fluid distribution. An accurate estimation of the Cole parameters is essential for the Body Composition Assessment (BCA) and the estimation process depends on several factors. One of them is the upper frequency limit used for the estimation and the other is the number of measured frequencies in the measurement frequency range. Both of them impose requirements on the measurement hardware, influencing largely in the complexity of the bioimpedance spectrometer. In this work an analysis of the error obtained when estimating the Cole parameters with several frequency ranges and different number of frequencies has been performed. The study has been done on synthetic EBIS data obtained from experimental Total Right Side (TRS) measurements. The results suggest that accurate estimations of R0 and R∞ for BCA measurements can be achieved using much narrower frequency ranges and quite fewer frequencies than electrical bioimpedance spectrometers commercially available nowadays do.

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  • 78.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Ferreira, Javier
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Marquez, Juan Carlos
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Conductive Polymer Films as Textrodes for Biopotential Sensing2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Introduction: After several years of progresses in textile technology and wearable measurement instrumentation, applications of wearable textile-electronics systems are arising providing a stable background for commercial applications. So far, the available commercial solutions are centered on fitness applications and mostly based in the acquisition of heart rate through Textile Electrodes (Textrodes) based on metallic threads or on conductive rubber compounds. Methods and Materials: In this work a novel material approach is presented to produce Textrodes for acquisition of Electrocardiographic (ECG) signals using a conductive polypropylene (PP1386 from Premix, Finland) polymer material. The polymer was film extruded into thin films, and used as such in the Textrode. Conductive Polymer Films (CPF) have been used to produce Textrodes, and its measurement performance has been compared with the ECG signals obtained with commercial Textrode fabrics and conventional Ag/AgCl electrodes. In order to set up the same measurement conditions, a chest strap tailored to host the testing electrodes has been used. Results: The close resemblance of the ECG acquired with the textile fabric electrodes, the Ag/AgCl electrodes and the PP1386 CPF electrodes suggest that the Polymer Electrodes PP1386 are a feasible alternative to the current textile fabrics that use silver thread as conductive material and also to conductive rubber material. Discussion & Conclusion: The availability of the Conductive Polymer Electrode PP1386 in a film form allows the manufacturing of electrodes by conventional textile processes, like lamination or sewing, therefore facilitating the transition from lab prototyping to industrial manufacturing. Replacing the traditional silver thread as conductive element in the fabrication of Textrodes will definitely reduce the material cost per Textrode. Biocompatibility issues and manufacturability issues must be addressed but the exhibited functional performance is showing encouraging results.

  • 79.
    Seoane Martinez, Fernando
    et al.
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Lindecrantz, Kaj
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Method and apparatus for brain damage detection2011Patent (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    The present invention comprises method and apparatus for detecting injury resulting in pathological processes affecting tissue within a portion of the body in a mammal, particularly a human brain. Said method comprises the steps of applying a first and a second pair of electrodes around the periphery of the portion, generating an alternating current at a known current level and applying said current between the first pair of electrodes, detecting and measuring the alternating voltage developed between the second pair of electrodes, and calculating the impedance of said portion. Further, the alternating current is applied between the first pair of electrodes in a series of increasing frequencies ranging within a known spectrum, and the resistance and the reactance for each frequency are detected and plotted against said frequency. The electrical impedance of said portion is calculated for each frequency and plotted into an impedance plot. Said resistance-reactance-and impedance-plots are finally analyzed, and any notable changes compared to normal spectrum profiles and plots are detected and evaluated.

  • 80.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Macias, Raul
    Bragos, Ramon
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Simple Voltage-Controlled Current Source for Wideband Electrical Bioimpedance Spectroscopy: Circuit Dependences2011Ingår i: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 22, nr 11, s. 115801-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, the single Op-Amp with load-in-the-loop topology as a current source is revisited. This circuit topology was already used as a voltage-controlled current source (VCCS) in the 1960s but was left unused when the requirements for higher frequency arose among the applications of electrical bioimpedance (EBI). The aim of the authors is not only limited to show that with the currently available electronic devices it is perfectly viable to use this simple VCCS topology as a working current source for wideband spectroscopy applications of EBI, but also to identify the limitations and the role of each of the circuit components in the most important parameter of a current for wideband applications: the output impedance. The study includes the eventual presence of a stray capacitance and also an original enhancement, driving with current the VCCS. Based on the theoretical analysis and experimental measurements, an accurate model of the output impedance is provided, explaining the role of the main constitutive elements of the circuit in the source's output impedance. Using the topologies presented in this work and the proposed model, any electronic designer can easily implement a simple and efficient current source for wideband EBI spectroscopy applications, e.g. in this study, values above 150 kΩ at 1 MHz have been obtained, which to the knowledge of the authors are the largest values experimentally measured and reported for a current source in EBI at this frequency

  • 81.
    Marquez Ruiz, Juan Carlos
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skin-Electrode Contact Area in Electrical Bioimpedance Spectroscopy. Influence in Total Body Composition Assessment.2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    Electrical Bioimpedance Spectroscopy (EBIS) has been widely use for assessment of total body composition and fluid distribution. (EBIS) measurements are commonly performed with electrolytic electrodes placed on the wrist and the ankle with a rather small skin–electrode contact area. The use of textile garments for EBI requires the integration of textrodes with a larger contact area surrounding the limbs in order to compensate the absence of electrolytic medium commonly present in traditional Ag/AgCl gel electrodes. Recently it has been shown that mismatch between the measurements electrodes might cause alterations on the EBIS measurements. When performing EBIS measurements with textrodes certain differences have been observed, especially at high frequencies, respect the same EBIS measurements using Ag/AgCl electrodes. In this work the influence of increasing the skinelectrode area on the estimation of body composition parameters has been study performing experimental EBIS measurement. The results indicate that an increment on the area of the skin-electrode interface did produce noticeable changes in the bioimpedance spectra as well as in the body composition parameters. This influence must be taken into consideration when designing and testing textile-enable EBIS measurement systems.

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    FULLTEXT01
  • 82.
    Seoane, Fernando
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Rempfler, Markus
    Marquez, Juan Carlos
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Textile-enabled Instrumentation for Impedance Cardiographic Signals2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Research efforts in the areas of Electrical Bioimpedance (EBI) and textile materials with conductive properties have contributed to the proliferation of research projects aiming to test the feasibility of implementing Textile-enabled instrumentation for performing EBI measurements. Most of the work done has been focused on the electrical characterization of the Textrodes (textile electrodes) and on spectroscopy applications of EBI like early detection of Cardiogenic Pulmonary Edema. In this work, a garment composed of two belts containing Textrodes made of conductive Velcro, loops-type, has been manufactured. Both, the abdomen and the neck belts, have four Textrodes connected through a conductive fabric Technik Tex P-130+ Shieldex fabric in pairs. This way, a tetrapolar EBI measurement between the neck and the chest is performed, implementing a typical band electrode arrangement [1] approach with the two belts. Using a custom-made device Respimon that measures the electrical cardiac activity with a 1-lead ECG and a tetrapolar EBI measurement at 50kHz of a portion of the body, and the Textrode garment, the ICG and ECG signals have been recorded and compared with the recordings obtained with Ag/AgCl electrodes placed in the same positions. The resemblance of the ICG and ECG signals obtained with both the Ag/AgCl electrodes and the Textrode garment confirms the feasibility of using Textrodes to perform measurements of cardiac impedance. There are several useful hemodynamic parameters that can be extracted from the ICG signal in combination with the ECG signal. The availability of a Textrode garment, easy to wear and that produces reliable ICG measurements, would contribute to present ICG monitoring as feasible technology for implementing personalized healthcare monitoring systems, especially for e-health applications of heart failure patients management.

  • 83.
    Seoane Martínez, Fernando
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Marquez, J. C.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Ferreira, Javier
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Buendia, Ruben
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    The Challenge of the Skin-Electrode Contact in Textile-enabled Electrical Bioimpedance Measurements for Personalized Healthcare Monitoring Applications2011Ingår i: Biomedical Engineering, Trends in Materials Science / [ed] AN Laskovski, InTech , 2011Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Textile technology has gone through a remarkable development in the field of Smart Textiles and more specifically in the area of conductive fabrics and yarns. Important research efforts have been done worldwide and especially in Europe, where the EUcommission has supported several research projects in the near past e.g. BIOTEX IST-2004- 016789, CONTEXT IST- 2004-027291 and MyHeart IST-2002-507816. As a result of such worldwide R&D efforts, textile sensors and electrodes are currently available commercially. Nowadays there are even consumer products with textile sensing technology for heart rate monitoring integrated in the apparel e.g. Adistar Fusion T-shirt from Adidas or the Numetrex’s Cardio shirt. Since one of the main areas of focus where R&D efforts have been concentrated is Personalized Healthcare Monitoring (PHM) and the fact that most of the efforts developing textile sensors have been focused on developing electrodes for biopotential signals recording, it is natural that the main targeted application has been the acquisition of electrical biopotentials and especially monitoring the ElectroCardioGraphic activity, but also other types of textile sensors have been investigated e.g. textile stretching sensor (Mattmann et al., 2008). Nowadays textile-enable stretch sensors are available commercially like the one manufactured by Merlin Systems. While the application of this type of sensor aims at other applications than biopotential recordings, an important area of application of stretch sensors still is PHM and fitness. This type of sensors can be used for respiration monitoring or plethysmography applications.

  • 84.
    Buendia, Ruben
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Seoane Martínez, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Gil-Pita, R.
    A Novel Approach for Removing the Hook Effect Artefact from Electrical Bioimpedance Spectroscopy Measurements2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    Very often in Electrical Bioimpedance (EBI) spectroscopy measurements the presence of stray capacitances creates a measurement artefact commonly known as Hook Effect. Such an artefact creates a hook-alike deviation of the EBI data noticeable when representing the measurement on the impedance plane. Such Hook Effect is noticeable at high frequencies but it also causes a data deviation at lower measurement frequencies. In order to perform any accurate analysis of the EBI spectroscopy data, the influence of the Hook Effect must be removed. An established method to compensate the hook effect is the well known Td compensation, which consists on multiplying the obtained spectrum, Zmeas(ω) by a complex exponential in the form of exp[jωTd]. Such a method cannot correct entirely the Hook Effect since the hook-alike deviation occurs a broad frequency range in both magnitude and phase of the measured impedance, and by using a scalar value for Td. First a scalar only modifies the phase of the measured impedance and second, a single value can truly corrects the Hook Effect only at a single frequency. In addition, the process to select a value for the scalar Td by an iterative process with the aim to obtain the best Cole fitting lacks solid scientific grounds. In this work the Td compensation method is revisited and a modified approach for correcting the Hook Effect including a novel method for selecting the correcting values is proposed. The initial validation results confirm that the proposed method entirely corrects the Hook Effect at all frequencies.

  • 85.
    Ferreira, Javier
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Ansede, Antonio
    Bragos, Ramon
    AD5933-based Spectrometer for Electrical Bioimpedance Applications2010Ingår i: Journal of Physics: Conference Series, Institute of Physics Publishing Ltd. , 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    To build an Electrical Bioimpedance (EBI) spectrometer using the Impedance Measurement System-On-Chip AD5933 together with a 4-Electrode Analog Front End (4E-AFE) has been proven practicable. Such small measurement devices can make possible several new applications of EBI technology, especially when combined with functional textiles, which can enable wearable applications for personal health and home monitoring. After the implementation and functional validation of the 4E-AFE-enabled spectrometer, the next natural step is to validate for which EBI applications the 4E-AFE-enabled system is suitable. To test the applicability of this novel spectrometer on several EBI applications, 2R1C equivalents models have been experimentally obtained and impedance spectroscopy measurements have been performed with the system under study and with the SFB7 EBI spectrometer manufactured by ImpediMed. The 2R1C circuit parameters have been estimated with the BioImp software from the spectra obtained with both EBI spectrometers and the estimated values have been compared with the original values used in each circuit model implementation. The obtained results indicated that the 4E-AFE-enabled system cannot beat the performance of the SFB7 in accuracy but it performs better in preciseness. In any case the overall performance indicates that the 4E-AFE-enabled system can perform spectroscopy measurements in the frequency range from 5 to 100 kHz.

  • 86.
    Seoane Martínez, Fernando
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Buendia, Ruben
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Gil-Pita, R.
    Cole Parameter Estimation from Electrical Bioconductance Spectroscopy Measurements2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    Several applications of Electrical Bioimpedance (EBI) make use of Cole parameters as base of their analysis, therefore Cole parameters estimation has become a very common practice within Multifrequency- and EBI spectroscopy. EBI measurements are very often contaminated with the influence of parasitic capacitances, which contributes to cause a hook-alike measurement artifact at high frequencies in the EBI obtained data. Such measurement artifacts might cause wrong estimations of the Cole parameters, contaminating the whole analysis process and leading to wrong conclusions. In this work, a new approach to estimate the Cole parameters from the real part of the admittance, i.e. the conductance, is presented and its performance is compared with the results produced with the traditional fitting of complex impedance to a depressed semi-circle. The obtained results prove that is feasible to obtain the full Cole equation from only the conductance data and also that the estimation process is safe from the influence capacitive leakage.

  • 87.
    Marquez, Juan Carlos
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Seoane, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Välimaki, Elina
    Högskolan i Borås, Institutionen Textilhögskolan.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Comparison of Dry-textile Electrodes for Electrical Bioimpedance Spectroscopy Measurements.2010Ingår i: Journal of Physics: Conference Series, Institute of Physics Publishing Ltd. , 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    Electrodes have been widely studied for biopotentials recordings, specially for monitoring the cardiac activity. Commercially available applications, such as Adistar T-shirt and Textronics Cardioshirt, have proved a good performance for heart rate monitoring and are available worldwide. Textile technology can also be used for Electrical Bioimpedance Spectroscopy measurements enabling home and personalized health monitoring applications however solid ground research about the measurement performance of the electrodes must be done prior to the development of any textile-enabled EBI application. In this work a comparison of the measurement performance of two different types of dry-textile electrodes and manufacturers has been performed against standardized RedDot 3M Ag/AgCl electrolytic electrodes. 4-Electrode, whole body, Ankle-to-Wrist EBI measurements have been taken with the Impedimed spectrometer SFB7 from healthy subjects in the frequency range of 3kHz to 500kHz. Measurements have been taken with dry electrodes at different times to study the influence of the interaction skin-electrode interface on the EBI measurements. The analysis of the obtained complex EBI spectra shows that the measurements performed with textile electrodes produce constant and reliable EBI spectra. Certain deviation can be observed at higher frequencies and the measurements obtained with Textronics and Ag/AgCl electrodes present a better resemblance. Textile technology, if successfully integrated it, may enable the performance of EBI measurements in new scenarios allowing the rising of novel wearable monitoring applications for home and personal care as well as car safety

  • 88.
    Marquez, J. C.
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Seoane Martínez, Fernando
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Välimäki, E.
    Högskolan i Borås, Institutionen Textilhögskolan.
    Lindecrantz, Kaj
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Comparison of Dry-Textile Electrodes for Electrical Bioimpedance Spectroscopy Measurements2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    Textile Electrodes have been widely studied for biopotentials recordings, specially for monitoring the cardiac activity. Commercially available applications, such as Adistar T-shirt and Textronics Cardioshirt, have proved a good performance for heart rate monitoring and are available worldwide. Textile technology can also be used for Electrical Bioimpedance Spectroscopy measurements enabling home and personalized health monitoring applications however solid ground research about the measurement performance of the electrodes must be done prior to the development of any textile-enabled EBI application. In this work a comparison of the measurement performance of two different types of dry-textile electrodes and manufacturers has been performed against standardized RedDot 3M Ag/AgCl electrolytic electrodes. 4-Electrode, whole body, Ankle-to-Wrist EBI measurements have been taken with the Impedimed spectrometer SFB7 from healthy subjects in the frequency range of 3kHz to 500kHz. Measurements have been taken with dry electrodes at different times to study the influence of the interaction skin-electrode interface on the EBI measurements. The analysis of the obtained complex EBI spectra shows that the measurements performed with textile electrodes produce constant and reliable EBI spectra. Certain deviation can be observed at higher frequencies and the measurements obtained with Textronics and Ag/AgCl electrodes present a better resemblance. Textile technology, if successfully integrated it, may enable the performance of EBI measurements in new scenarios allowing the rising of novel wearable monitoring applications for home and personal care as well as car safety.

  • 89.