Change search
Link to record
Permanent link

Direct link
BETA
Publications (10 of 29) Show all publications
Vega-Barbas, M., Diaz-Olivares, J. A., Lu, K., Forsman, M., Seoane, F. & Abtahi, F. (2019). P-Ergonomics Platform: Toward Precise, Pervasive, and Personalized Ergonomics using Wearable Sensors and Edge Computing. Sensors, 19(5), Article ID 1225.
Open this publication in new window or tab >>P-Ergonomics Platform: Toward Precise, Pervasive, and Personalized Ergonomics using Wearable Sensors and Edge Computing
Show others...
2019 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 19, no 5, article id 1225Article in journal (Refereed) Published
Abstract [en]

Preventive healthcare has attracted much attention recently. Improving people's lifestyles and promoting a healthy diet and wellbeing are important, but the importance of work-related diseases should not be undermined. Musculoskeletal disorders (MSDs) are among the most common work-related health problems. Ergonomists already assess MSD risk factors and suggest changes in workplaces. However, existing methods are mainly based on visual observations, which have a relatively low reliability and cover only part of the workday. These suggestions concern the overall workplace and the organization of work, but rarely includes individuals' work techniques. In this work, we propose a precise and pervasive ergonomic platform for continuous risk assessment. The system collects data from wearable sensors, which are synchronized and processed by a mobile computing layer, from which exposure statistics and risk assessments may be drawn, and finally, are stored at the server layer for further analyses at both individual and group levels. The platform also enables continuous feedback to the worker to support behavioral changes. The deployed cloud platform in Amazon Web Services instances showed sufficient system flexibility to affordably fulfill requirements of small to medium enterprises, while it is expandable for larger corporations. The system usability scale of 76.6 indicates an acceptable grade of usability.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
disease prevention, occupational healthcare, P-Ergonomics, precision ergonomics, musculoskeletal disorders, smart textiles, wearable sensors, wellbeing at work
National Category
Occupational Health and Environmental Health
Identifiers
urn:nbn:se:kth:diva-249891 (URN)10.3390/s19051225 (DOI)000462540400244 ()30862019 (PubMedID)2-s2.0-85062856566 (Scopus ID)
Available from: 2019-04-26 Created: 2019-04-26 Last updated: 2019-04-26Bibliographically approved
Hafid, A., Benouar, S., Kedir-talha, M., Abtahi, F., Attari, M. & Seoane, F. (2018). Full Impedance Cardiography Measurement Device Using Raspberry PI3 and System-on-Chip Biomedical Instrumentation Solutions. IEEE journal of biomedical and health informatics, 22(6), 1883-1894
Open this publication in new window or tab >>Full Impedance Cardiography Measurement Device Using Raspberry PI3 and System-on-Chip Biomedical Instrumentation Solutions
Show others...
2018 (English)In: IEEE journal of biomedical and health informatics, ISSN 2168-2194, E-ISSN 2168-2208, Vol. 22, no 6, p. 1883-1894Article in journal (Refereed) Published
Abstract [en]

Impedance cardiography (ICG) is a noninvasive 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 presents a measurement system based on two System on Chip (SoC) solutions and Raspberry PI, implementing both a full three-lead ECG recorder and an impedance cardiographer, for educational and research development purposes. Raspberry PI is a platform supporting Do-I t-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 recordings 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.BiosignalPl.com, for open access under a Non Commercial-Share A like 4.0 International License.

Place, publisher, year, edition, pages
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2018
Keywords
AD5933, ADAS1000, bioimpedance, biosignal PI, biomedical instrumentation, cardiac monitoring, personalized healthcare, portable ECG, ICG, Raspberry PI3
National Category
Medical Biotechnology
Identifiers
urn:nbn:se:kth:diva-238525 (URN)10.1109/JBHI.2017.2783949 (DOI)000447833100019 ()29990025 (PubMedID)
Note

QC 20181106

Available from: 2018-11-06 Created: 2018-11-06 Last updated: 2018-11-06Bibliographically approved
Karbalaie, A., Etehadtavakol, M., Abtahi, F., Fatemi, A., Emrani, Z. & Erlandsson, B.-E. (2018). Image Enhancement Effect on Inter and Intra-observer Reliability of Nailfold Capillary Assessment. Microvascular Research
Open this publication in new window or tab >>Image Enhancement Effect on Inter and Intra-observer Reliability of Nailfold Capillary Assessment
Show others...
2018 (English)In: Microvascular Research, ISSN 0026-2862, E-ISSN 1095-9319Article in journal (Refereed) Published
Abstract [en]

Background: Nailfold capillaroscopy (NC) is a diagnostic imaging technique that is used to assess the blood capillary network in the nailfold area. NC is routinely used for patients with microcirculation problems, such as systemic sclerosis and other connective tissue diseases.  Experts commonly use subjective evaluation as a reference point in images of nailfold video capillaroscopy, so it is important to reduce the inherent ambiguities in human judgment and diagnosis. Image quality is an important factor that affects measurement error and assessment time of NC images.

Objective: In this study, a new image enhancement technique was introduced and evaluated subjectively.

Methods: In total, 475 nailfold video capillaroscopy images from 18 healthy subjects and 41 systemic lupus erythematosus patients were used. The images were randomly divided into two sets, one each with 275 and 200. Eight independent observers who were familiar with the capillaroscopy technique participated in this study. The set of 275 images was evaluated by three observers with the forced–choice pairwise comparison method. Elliptic broken line (EBL) was used to count the number of capillaries. The intra- and inter-observer reliability of the original and enhanced images was evaluated on 200 images by five observers.

Result: Except for eight images, all observers preferred the enhanced images in the visual quality comparison method. The intra-class correlation coefficient (ICC) of intra- and inter-observer reliability increased from 0.76-0.84 to 0.82-0.89, respectively, when using the enhancement method.

Conclusion: By improving the image quality, more capillary details will be visible, and an observer can document more details that may not be visible in the original image and can do so more efficiently.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Nailfold capillaroscopy; Image enhancement; Inter and intra-observer reliability; Capillary density; Systemic lupus erythematosus
National Category
Medical and Health Sciences
Research subject
Medical Technology
Identifiers
urn:nbn:se:kth:diva-231959 (URN)10.1016/j.mvr.2018.06.005 (DOI)000449037600016 ()2-s2.0-85051111896 (Scopus ID)
Note

QC 20180821

Available from: 2018-07-05 Created: 2018-07-05 Last updated: 2018-11-20Bibliographically approved
Yang, L., Lu, K., Abtahi, F., Lindecrantz, K., Seoane, F., Forsman, M. & Eklund, J. (2017). A pilot study of using smart clothes for physicalworkload assessment. In: JOY AT WORK: . Paper presented at Conference Proceedings of Nordic Ergonomics Society 49th Annual Conference (pp. 169-170). Lund, Sweden
Open this publication in new window or tab >>A pilot study of using smart clothes for physicalworkload assessment
Show others...
2017 (English)In: JOY AT WORK, Lund, Sweden, 2017, p. 169-170Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Lund, Sweden: , 2017
Keywords
Energy expenditure estimation, pulmonary ventilation, heart rate.
National Category
Production Engineering, Human Work Science and Ergonomics
Identifiers
urn:nbn:se:kth:diva-227864 (URN)978-91-7753-152-4 (ISBN)
Conference
Conference Proceedings of Nordic Ergonomics Society 49th Annual Conference
Note

QC 20180614

Available from: 2018-05-14 Created: 2018-05-14 Last updated: 2018-06-14Bibliographically approved
Gyllencreutz, E., Lu, K., Abtahi, F., Lindecrantz, K., Nordström, L., Lindqvist, P. & Holzmann, M. (2017). Characteristics of variable decelerations and prediction of fetal acidemia. Paper presented at 37th Annual Pregnancy Meeting of the Society-for-Maternal-Fetal-Medicine (SMFM), JAN 23-28, 2017, Las Vegas, NV. American Journal of Obstetrics and Gynecology, 216(1), S507-S507
Open this publication in new window or tab >>Characteristics of variable decelerations and prediction of fetal acidemia
Show others...
2017 (English)In: American Journal of Obstetrics and Gynecology, ISSN 0002-9378, E-ISSN 1097-6868, Vol. 216, no 1, p. S507-S507Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Obstetrics, Gynecology and Reproductive Medicine
Identifiers
urn:nbn:se:kth:diva-219522 (URN)000414256403203 ()
Conference
37th Annual Pregnancy Meeting of the Society-for-Maternal-Fetal-Medicine (SMFM), JAN 23-28, 2017, Las Vegas, NV
Note

QC 20171208

Available from: 2017-12-08 Created: 2017-12-08 Last updated: 2017-12-08Bibliographically approved
Karbalaie, A., Abtahi, F., Fatemi, A., Etehadtavakol, M., Emrani, Z. & Erlandsson, B.-E. (2017). Elliptical broken line method for calculating capillary density in nailfold capillaroscopy: Proposal and evaluation. Microvascular Research, 113, 1-8
Open this publication in new window or tab >>Elliptical broken line method for calculating capillary density in nailfold capillaroscopy: Proposal and evaluation
Show others...
2017 (English)In: Microvascular Research, ISSN 0026-2862, E-ISSN 1095-9319, Vol. 113, p. 1-8Article in journal (Refereed) Published
Abstract [en]

Nailfold capillaroscopy is a practical method for identifying and obtaining morphological changes in capillaries which might reveal relevant information about diseases and health. Capillaroscopy is harmless, and seems simple and repeatable. However, there is lack of established guidelines and instructions for acquisition as well as the interpretation of the obtained images; which might lead to various ambiguities. In addition, assessment and interpretation of the acquired images are very subjective. In an attempt to overcome some of these problems, in this study a new modified technique for assessment of nailfold capillary density is introduced. The new method is named elliptic broken line (EBL) which is an extension of the two previously known methods by defining clear criteria for finding the apex of capillaries in different scenarios by using a fitted elliptic. A graphical user interface (GUI) is developed for pre-processing, manual assessment of capillary apexes and automatic correction of selected apexes based on 90° rule. Intra- and inter-observer reliability of EBL and corrected EBL is evaluated in this study. Four independent observers familiar with capillaroscopy performed the assessment for 200 nailfold videocapillaroscopy images, form healthy subject and systemic lupus erythematosus patients, in two different sessions. The results show elevation from moderate (ICC = 0.691) and good (ICC = 0.753) agreements to good (ICC = 0.750) and good (ICC = 0.801) for intra- and inter-observer reliability after automatic correction of EBL. This clearly shows the potential of this method to improve the reliability and repeatability of assessment which motivates us for further development of automatic tool for EBL method.

Place, publisher, year, edition, pages
Academic Press, 2017
Keywords
Capillary density, Nailfold capillaroscopy, Number of papillae, Reliability, Repeatability
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:kth:diva-207279 (URN)10.1016/j.mvr.2017.04.002 (DOI)000404692200001 ()28414021 (PubMedID)2-s2.0-85017510457 (Scopus ID)
Note

QC 20170619

Available from: 2017-06-19 Created: 2017-06-19 Last updated: 2018-11-20Bibliographically approved
Karbalaie, A., Fatemi, A., Etehadtavakol, M., Abtahi, F., Emrani, Z. & Erlandsson, B.-E. (2016). Counting Capillaries in Nailfold Capillaroscopy:State of the Art and a Proposed Method. In: 2016 IEEE EMBS CONFERENCE ON BIOMEDICAL ENGINEERING AND SCIENCES (IECBES): . Paper presented at Conference on Biomedical Engineering and Sciences (IECBES) (pp. 170-174). IEEE
Open this publication in new window or tab >>Counting Capillaries in Nailfold Capillaroscopy:State of the Art and a Proposed Method
Show others...
2016 (English)In: 2016 IEEE EMBS CONFERENCE ON BIOMEDICAL ENGINEERING AND SCIENCES (IECBES), IEEE, 2016, , p. 5p. 170-174Conference paper, Published paper (Refereed)
Abstract [en]

Capillaries play a crucial role in the microcirculatory system by exchanging metabolic substrates and waste products between blood and various tissues. The behavior of capillaries is affiliated with the number of capillaries per unit volume of tissue. Among the various noninvasive techniques available for analyzing skin microcirculation, nailfold capillaroscopyis considered to be a simple and easy-to-perform technique that allows a direct in-vivo visualization of the capillary network.Capillary density is one of the most important parameters in the studies involving capillaroscopy images. Capillary density in most of studies is defined as the number of capillaries in a one-millimeter span of the distal row in each finger or toe. This definition is silent about counting or excluding the number of the capillary with different shapes. However, there is no single standard for counting the number of capillaries in a span of one millimeter. In this paper, a novel method is proposed for determining the nailfold capillary density. This method is a modified combination of two existing techniques: the direct observation and the 90◦ method.Compared to the two existing approaches, the proposed method is more straightforward and easy to use for cases in which the capillaries have different shapes and sizes. Through different examples, we have shown how this method can be used to select the apex point of the capillary and subsequently count the number of capillaries with several papillae.

Place, publisher, year, edition, pages
IEEE, 2016. p. 5
National Category
Medical and Health Sciences
Research subject
Medical Technology
Identifiers
urn:nbn:se:kth:diva-224836 (URN)10.1109/IECBES.2016.7843437 (DOI)000400605700035 ()2-s2.0-85015704316 (Scopus ID)
Conference
Conference on Biomedical Engineering and Sciences (IECBES)
Note

QC 20180327

Available from: 2018-03-26 Created: 2018-03-26 Last updated: 2018-11-20Bibliographically approved
Abtahi, F. (2016). Towards Heart Rate Variability Tools in P-Health: Pervasive, Preventive, Predictive and Personalized. (Doctoral dissertation). Stockholm: KTH Royal Institute of Technology
Open this publication in new window or tab >>Towards Heart Rate Variability Tools in P-Health: Pervasive, Preventive, Predictive and Personalized
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Heart rate variability (HRV) has received much attention lately. It has been shown that HRV can be used to monitor the autonomic nervous system and to detect autonomic dysfunction, especially vagal dysfunction. Reduced HRV is associated with several diseases and has also been suggested as a predictor of poor outcomes and sudden cardiac death. HRV is, however, not yet widely accepted as a clinical tool and is mostly used for research. Advances in neuroimmunity with an improved understanding of the link between the nervous and immune systems have opened a new potential arena for HRV applications. An example is when systemic inflammation and autoimmune disease are primarily caused by low vagal activity; it can be detected and prognosticated by reduced HRV. This thesis is the result of several technical development steps and exploratory research where HRV is applied as a prognostic diagnostic tool with preventive potential. The main objectives were 1) to develop an affordable tool for the effective analysis of HRV, 2) to study the correlation between HRV and pro-inflammatory markers and the potential degree of activity in the cholinergic anti-inflammatory pathway, and 3) to develop a biofeedback application intended for support of personal capability to increase the vagal activity as reflected in increased HRV. Written as a compilation thesis, the methodology and the results of each study are presented in each appended paper. In the thesis frame/summary chapter, a summary of each of the included papers is presented, grouped by topic and with their connections. The summary of the results shows that the developed tools may accurately register and properly analyse and potentially influence HRV through the designed biofeedback game. HRV can be used as a prognostic tool, not just in traditional healthcare with a focus on illness but also in wellness. By using these tools for the early detection of decreased HRV, prompt intervention may be possible, enabling the prevention of disease. Gamification and serious gaming is a potential platform to motivate people to follow a routine of exercise that might, through biofeedback, improve HRV and thereby health.

Abstract [sv]

Hjärtfrekvensvariabilitet (HRV) har senaste tiden rönt en hel del uppmärksamhet och flera teknikerför analys av HRV i tids- resp. frekvensområdet samt medels icke-linjära metoder har utvecklats.Det har visats att HRV kan användas för att övervaka det autonoma nervsystemet (ANS) blandannat för att upptäcka särskilt vagala störningar inom ANS. Minskad HRV förknippas med flerasjukdomar såsom diabetes, reumatoid artrit, depression, kronisk hjärtsjukdom och har ävenföreslagits som prediktor för dålig prognos och plötslig hjärtdöd. HRV är dock ännu inte allmäntaccepterat som ett kliniskt verktyg utan används främst inom forskning. Framsteg inomneuroimmunitetsområdet med ökad förståelse för sambandet mellan nerv- och immunsystem, haröppnat en nytt potentiell område för HRV-applikationer. Ett exempel är när systemiskinflammationoch autoimmun sjukdom primärt orsakas av låg vagal aktivitet, vilket kan upptäckas ochprognostiseras via minskad HRV. Denna avhandling är resultatet av flera tekniska utvecklingsstegoch explorativ forskning där HRV tillämpas i syfte att utveckla ett prognostiskt diagnostiskt verktygmed förebyggande potential. Huvudsyften har varit: 1) att utveckla ett prisvärt verktyg för eneffektiv och enkel analys av HRV 2) att studera sambandet mellan HRV och pro-inflammatoriskamarkörer och därigenom potentiellt återspegla graden av aktivitet i den kolinergaantiinflammatoriska effektorvägen 3) att utveckla datorprogramvara för ett biologisktåterkopplingssystem där individen med egen träning ökar sin vagala aktivitet vilket sedanåterspeglas i en ökad HRV. I denna sammanläggningsavhandling finns utförlig beskrivning av varjeingående studies metod och resultat artikar I-VI. I ramberättelsen presenteras en kortsammanfattning av metoder och resultat, grupperade efter ämne och sammanhang.Sammanfattningsvis visar resultaten att de utvecklade verktygen adekvat registrerar och analyserarHRV korrekt enkelt , samt att HRV kan påverkas av spel-träning. HRV i framtaget koncept harpotential att användas som ett skarpt prognostiskt verktyg, inte bara för traditionell vård med fokuspå sjukdom, utan också inom friskvård. Framtagna verktyg möjliggör tidig upptäckt av minskadHRV, snabb intervention och prevention. Spelifiering med seriöst spelande utgör en potentiellplattform som motiverar en träningsrutin och som genom återkoppling kan öka HRV och därmedvälmåendet.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2016. p. 50
Series
TRITA-STH : report, ISSN 1653-3836 ; 2016:5
Keywords
Heart Rate Variability, Cholinergic Anti-inflammatory Pathway, Autonomic Nervous System, Vagal activity, Biofeedback, Gamification, Serious Gaming, Inflammatory Markers, Raspberry PI
National Category
Other Medical Engineering
Research subject
Medical Technology
Identifiers
urn:nbn:se:kth:diva-190182 (URN)978-91-7729-069-8 (ISBN)
External cooperation:
Public defence
2016-09-26, T2, Blickagången 20, Stockholm, 10:00 (English)
Opponent
Supervisors
Funder
VINNOVA
Note

QC 20160902

Available from: 2016-09-02 Created: 2016-08-11 Last updated: 2016-09-04Bibliographically approved
Wollmann, T., Abtahi, F., Eghdam, A., Seoane, F., Lindecrantz, K., Haag, M. & Koch, S. (2016). User-Centred Design and Usability Evaluation of a Heart Rate Variability Biofeedback Game. IEEE Access, 4, 5531-5539
Open this publication in new window or tab >>User-Centred Design and Usability Evaluation of a Heart Rate Variability Biofeedback Game
Show others...
2016 (English)In: IEEE Access, E-ISSN 2169-3536, Vol. 4, p. 5531-5539Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2016
Keywords
Autonomic nervous system;Biofeedback;Bioinformatics;Biological control systems;Games;Heart rate variability;Informatics;Multitasking;Patient rehabilitation;Resonant frequency;Consumer Health Informatics (CHI);Exergaming;Gamification for Health;Heart Rate Variability (HRV) Biofeedback;Patient Motivation;Usability
National Category
Human Computer Interaction Other Medical Engineering
Research subject
Medical Technology; Computer Science
Identifiers
urn:nbn:se:kth:diva-191359 (URN)10.1109/ACCESS.2016.2601882 (DOI)000395469000001 ()2-s2.0-85027047802 (Scopus ID)
Note

QC 20160907

Available from: 2016-08-30 Created: 2016-08-30 Last updated: 2018-09-19Bibliographically approved
Abtahi, F., Lu, K., Guangchao, L., Rödby, K. & Seoane, F. (2015). A Knitted Garment using Intarsia Technique for Heart Rate Variability Biofeedback: Evaluation of Initial Prototype.. In: : . Paper presented at Annual I-Pack KTH-VINNOVA Excellence Center Workshop, 2015.
Open this publication in new window or tab >>A Knitted Garment using Intarsia Technique for Heart Rate Variability Biofeedback: Evaluation of Initial Prototype.
Show others...
2015 (English)Conference paper, Poster (with or without abstract) (Other academic)
Keywords
Intarsia, textile-electronic integration
National Category
Medical Engineering Textile, Rubber and Polymeric Materials
Research subject
Människan i vården
Identifiers
urn:nbn:se:kth:diva-181871 (URN)
Conference
Annual I-Pack KTH-VINNOVA Excellence Center Workshop, 2015
Note

QC 20160229

Available from: 2016-02-03 Created: 2016-02-05 Last updated: 2017-08-15Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-7807-8682

Search in DiVA

Show all publications