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Soroudi, A., Hernández, N., Berglin, L. & Nierstrasz, V. (2019). Electrode placement in electrocardiography smart garments: A review. Journal of Electrocardiology, 57, 27-30
Open this publication in new window or tab >>Electrode placement in electrocardiography smart garments: A review
2019 (English)In: Journal of Electrocardiology, ISSN 0022-0736, E-ISSN 1532-8430, Vol. 57, p. 27-30Article in journal (Refereed) Published
Abstract [en]

Wearable Electrocardiography (ECG) sensing textiles have been widely used due to their high flexibility, comfort, reusability and the possibility to be used for home-based and real-time measurements. Textile electrodes are dry and non-adhesive, therefor unlike conventional gel electrodes, they don't cause skin irritation and are more user-friendly especially for long-term and continuous monitoring outside the hospital. However, the challenge with textile electrodes is that the quality and reliability of recorded ECG signals by smart garments are more sensitive to different factors such as electrode placement, skin humidity, user activities and contact pressure. This review will particularly focus on the research findings regarding the influence of electrode placement on the quality of biosignal sensing, and will introduce the methods used by researchers to measure the optimal positions of the electrodes in wearable ECG garments. The review will help the designers to take into account different parameters, which affect the data quality, reliability and comfort, when selecting the electrode placement in a wearable ECG garment.

Keywords
Electrode placement, electrocardiography, ECG, wearable electronics, smart garments
National Category
Engineering and Technology
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-21721 (URN)10.1016/j.jelectrocard.2019.08.015 (DOI)000503909100007 ()2-s2.0-85071359617 (Scopus ID)
Projects
WearItMed
Funder
Swedish Foundation for Strategic Research
Available from: 2019-09-13 Created: 2019-09-13 Last updated: 2020-01-29Bibliographically approved
Soroudi, A., Skrifvars, M. & Nierstrasz, V. (2019). Novel Skin-Electrode Conductive Adhesives to Improve the Quality of Recorded Body Signals in Smart Medical Garments. MDPI Proceedings, 32
Open this publication in new window or tab >>Novel Skin-Electrode Conductive Adhesives to Improve the Quality of Recorded Body Signals in Smart Medical Garments
2019 (English)In: MDPI Proceedings, ISSN 2504-3900, Vol. 32Article in journal (Refereed) Published
Abstract [en]

A main barrier to widespread use of electrocardiography garments for long term heart monitoring of elderly and patients is a poor skin-electrode signal transfer because of a high contact impedance and sensitivity to movement. This leads to unwanted disturbances and errors in recorded signals when the patient moves or even breathe, affecting the reliability and quality of the signals especially for patients with dry/old skin. In two different projects at the University of Borås, we have developed two novel products to solve the above problem; (1) an ongoing project that has fabricated a reusable and sustainable electro-conductive adhesive applicable between the skin and high-porous textile electrodes, and (2) a patent-pending skin-electrode glue (BioEl Glue®) which is a biocompatible electro-conductive water-soluble glue used between skin and low-porous textile electrodes.

Keywords
contact impedance, skin electrode interface, textile electrodes, ECG garments, medical garments, electrocardiography garments, smart textile, wearable electronics, wearable ECG
National Category
Polymer Technologies
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-22341 (URN)10.3390/proceedings2019032009 (DOI)
Available from: 2019-12-29 Created: 2019-12-29 Last updated: 2020-06-01Bibliographically approved
Soroudi, A., Hernández, N., Wipenmyr, J. & Nierstrasz, V. (2019). Surface modification of textile electrodes to improve electrocardiography signals in wearable smart garment. Journal of materials science. Materials in electronics, 30(17), 16666-16675
Open this publication in new window or tab >>Surface modification of textile electrodes to improve electrocardiography signals in wearable smart garment
2019 (English)In: Journal of materials science. Materials in electronics, ISSN 0957-4522, E-ISSN 1573-482X, Vol. 30, no 17, p. 16666-16675Article in journal (Refereed) Published
Abstract [en]

Recording high quality biosignals by dry textile electrodes is a common challenge in medical health monitoring garments. The aim of this study was to improve skin–electrode interface and enhance the quality of recorded electrocardiography (ECG) signals by modification of textile electrodes embedded in WearItMed smart garment. The garment has been developed for long-term health monitoring in patients suffering from epilepsy and Parkinson’s disease. A skin-friendly electro-conductive elastic paste was formulated to coat and modify the surface of the knitted textile electrodes. The modifications improved the surface characteristics of the electrodes by promoting a more effective contact area between skin and electrode owing to a more even surface, fewer pores, greater surface stability against touch, and introduction of humidity barrier properties. The modifications decreased the skin–electrode contact impedance, and consequently improved the recorded ECG signals obviously when low pressure was applied to the electrodes, therefore contributed to greater patient comfort. The created contact surface allowed the natural humidity of the skin/sweat to ease the signal transfer between the electrode and the body, while introducing a shorter settling time and retaining moisture over a longer time. Microscopic images, ECG signal measurements, electrode–skin contact impedance at different pressures and times, and water absorbency were measured and reported.

Keywords
textile electrode, smart textile, ECG garment, surface modification
National Category
Textile, Rubber and Polymeric Materials
Research subject
Textiles and Fashion (General)
Identifiers
urn:nbn:se:hb:diva-21727 (URN)10.1007/s10854-019-02047-9 (DOI)000486022200088 ()2-s2.0-85071499887 (Scopus ID)
Projects
WearItMed
Funder
Swedish Foundation for Strategic Research
Available from: 2019-09-13 Created: 2019-09-13 Last updated: 2020-01-29
Seoane, F., Soroudi, A., Lu, K., Nilsson, D., Nilsson, M., Abtahi, F. & Skrifvars, M. (2019). Textile-Friendly Interconnection between Wearable Measurement Instrumentation and Sensorized Garments—Initial Performance Evaluation for Electrocardiogram Recordings. Sensors, 19(29), 4426
Open this publication in new window or tab >>Textile-Friendly Interconnection between Wearable Measurement Instrumentation and Sensorized Garments—Initial Performance Evaluation for Electrocardiogram Recordings
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2019 (English)In: Sensors, E-ISSN 1424-8220, Vol. 19, no 29, p. 4426-Article in journal (Refereed) Published
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.

Keywords
conductive polymers, wearable technology, smart textiles, textile–electronic integration
National Category
Engineering and Technology
Identifiers
urn:nbn:se:hb:diva-23229 (URN)10.3390/s19204426 (DOI)000497864700074 ()2-s2.0-85073476096 (Scopus ID)
Available from: 2020-05-25 Created: 2020-05-25 Last updated: 2022-02-10Bibliographically approved
Seoane, F., Soroudi, A., Abtahi, F., Lu, K. & Skrifvars, M. (2016). Printed Electronics Enabling a Textile-friendly Interconnection between Wearable Measurement Instrumentation & Sensorized Garments. In: : . Paper presented at idtechex Printed Electronics, Berlin, November 16-17, 2016.
Open this publication in new window or tab >>Printed Electronics Enabling a Textile-friendly Interconnection between Wearable Measurement Instrumentation & Sensorized Garments
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2016 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Medical Engineering Textile, Rubber and Polymeric Materials
Identifiers
urn:nbn:se:hb:diva-11674 (URN)
Conference
idtechex Printed Electronics, Berlin, November 16-17, 2016
Funder
VINNOVA, 2014-03413]
Available from: 2017-01-08 Created: 2017-01-08 Last updated: 2017-01-11Bibliographically approved
Soroudi, A. & Jakubowicz, I. (2013). Recycling of bioplastics, their blends and biocomposites: A review. European Polymer Journal, 49(10), 2839-2858
Open this publication in new window or tab >>Recycling of bioplastics, their blends and biocomposites: A review
2013 (English)In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 49, no 10, p. 2839-2858Article in journal (Refereed) Published
Abstract [en]

This review presents scientific findings concerning the recycling of bioplastics, their blends and thermoplastic biocomposites, with special focus on mechanical recycling of bio-based materials. The paper does not include bio-based commodity plastics such as bio-derived polyolefins that are identical to their petroleum-based counterparts and that can be recycled in the same way. During the past few years, recycling of biopolymers and their blends has been studied using both mechanical and chemical methods, whereas in biocomposites, the focus has been on mechanical recycling. This review goes through the findings on the recyclability of various materials, the strengths and weaknesses of applied methods, as well as the potential strategies and opportunities for future improvements. There are still many blends that have not been investigated for their recyclability. Information about commercially available blends containing bioplastics is summarised in the Appendix because of the importance of their possible effects on the conventional plastic recycling streams.

National Category
Chemical Engineering
Identifiers
urn:nbn:se:hb:diva-21724 (URN)10.1016/j.eurpolymj.2013.07.025 (DOI)
Funder
Mistra - The Swedish Foundation for Strategic Environmental Research
Available from: 2019-09-13 Created: 2019-09-13 Last updated: 2019-09-17Bibliographically approved
Soroudi, A. & Skrifvars, M. (2012). Electro-conductive polyblend fibers of Polyamide-6/polypropylene/polyaniline: electrical, morphological and mechanical characteristics. Polymer Engineering and Science, 52(7), 1606-1612
Open this publication in new window or tab >>Electro-conductive polyblend fibers of Polyamide-6/polypropylene/polyaniline: electrical, morphological and mechanical characteristics
2012 (English)In: Polymer Engineering and Science, ISSN 0032-3888, E-ISSN 1548-2634, Vol. 52, no 7, p. 1606-1612Article in journal (Refereed) Published
Abstract [en]

Melt spun drawn fibers were prepared using a ternary blend of PP/PA6/PANI-complex (polypropylene/polyamide-6/polyaniline-complex). Their electrical and mechanical properties were compared to those of binary blend fibers of PP/PANI-complex. The results of the morphological studies on 55:25:20 PP/PA6/PANI-complex ternary fibers were found to be in accordance with the predicted morphology for the observed conductivity vs. fiber draw ratio. The scanning electron microscopy (SEM) micrographs of the ternary blend illustrated at least a three-phase morphology of a matrix/core-shell dispersed phase style, with widely varying sizes of droplets. This resulted in a dispersed morphology that, in some parts of the blend, approached a bicontinuous/dispersed phase morphology due to coalescence of the small droplets. The matrix was PP and the core-shell dispersed phase was PA6 and PANI-complex, in which a part of the PANI-complex had encapsulated the PA6 phase and the remaining was solved/dispersed in the PA6 core, as later confirmed by X-ray mapping. When the ternary blend fibers were compared to the binary fibers, the formers were able to combine better conductivity (of an order of 10−3 S cm−1) with a greater tensile strength only at a draw ratio of 5. This indicated that the draw ratio is more critical for the ternary blend fibers, because both conductivity and tensile strength depended on the formation of fibrils from the core-shell dispersed phase of the PA6/PANI-complex.

Place, publisher, year, edition, pages
John Wiley & Sons, Inc., 2012
Keywords
Conductive yarn, smart textiles, polyanilini, polyamide, Resursåtervinning
National Category
Materials Engineering
Identifiers
urn:nbn:se:hb:diva-1482 (URN)10.1002/pen.23074 (DOI)000305473100025 ()2320/11914 (Local ID)2320/11914 (Archive number)2320/11914 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2019-09-17Bibliographically approved
Hooshmand, S., Soroudi, A. & Skrifvars, M. (2011). Electroconductive composite fibers by melt spinning of polypropylene/polyamide/carbon nanotubes. Synthetic metals, 161(15-16), 1731-1737
Open this publication in new window or tab >>Electroconductive composite fibers by melt spinning of polypropylene/polyamide/carbon nanotubes
2011 (English)In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 161, no 15-16, p. 1731-1737Article in journal (Refereed) Published
Abstract [en]

In this study, the blends of polypropylene/polyamide with carbon nanotubes (CNTs) have been prepared and melt spun to as-spun and drawn fibers. Thermal analysis showed that increasing the polyamide content, decreased the degree of crystallinity in the blends. Characterization of fibers showed that both conductivity and tensile strength have been improved by increasing the amount of polyamide in the blends as well as the melt blending temperature; furthermore, the morphology, electrical and mechanical properties of the blends were significantly influenced by adding 1 phr compatibilizer to the blend. The comparison between as-spun fibers and drawn fibers proved that although mechanical properties were improved after drawing, the electrical conductivity was decreased from the order of E−02 to E−06 (S/cm), due to applied draw-ratio of three.

Place, publisher, year, edition, pages
Elsevier, 2011
Keywords
conductive fiber, melt spinning, polypropylene (pp), polyamide (pa), carbon nanotube, Energi och material
National Category
Materials Engineering Polymer Chemistry
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-3171 (URN)10.1016/j.synthmet.2011.06.014 (DOI)2320/9265 (Local ID)2320/9265 (Archive number)2320/9265 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-11-29Bibliographically approved
Soroudi, A. (2011). Melt Spun Electro-Conductive Polymer Composite Fibers. (Doctoral dissertation). Chalmers University of Technology
Open this publication in new window or tab >>Melt Spun Electro-Conductive Polymer Composite Fibers
2011 (English)Doctoral thesis, monograph (Other academic)
Abstract [en]

One interesting approach is the development of conductive polymer composite fibers for innovative textile applications such as in sensors, actuators and electrostatic discharge. In this study, conductive polymer composite fibers were prepared using several different blends containing conductive components: a conjugated polymer (polyaniline-complex) and/or carbon nanotubes. Different factors such as processing parameters, the morphology of the initial blends and the final fibers, fiber draw ratio and material selection were studied separately to characterize their effects on the fiber properties. In binary blends of PP/polyaniline-complex, the processing conditions, the matrix viscosity and the fiber draw ratio had substantial effects on the electrical conductivity of the fibers and linearity of resistance-voltage dependence. These factors were associated with each other to create conductive pathways through maintaining an appropriate balance of fibril formation and breakage along the fiber. The blend morphology was defined as the initial size of the dispersed conductive phase (polyaniline-phase), which depended on the melt blending conditions as well as the PP matrix viscosity. Depending on the initial droplet phase size, an optimum draw ratio was necessary to obtain maximum conductivity by promoting fibril formation (sufficient stress) and preventing fibril breakage (no excess stress) to create continuous pathways of conductive phase. Ternary blend fibers of PP/PA6/polyaniline-complex illustrated at least three-phase morphology with matrix/core-shell dispersed phase style. When ternary fibers were compared to binary fibers, the former could combine better mechanical and electrical properties only at a specific draw ratio; this showed that draw ratio was a more determinant factor for the ternary fibers, as both conductivity and tensile strength depended on the formation of fibrils from the core-shell droplets of the PA6/polyaniline-complex through the polypropylene matrix. The achieved maximum conductivity so far was in the range of 10 S/cm to 10 S/cm, which for different samples were observed at different fiber draw ratios depending on the mixing conditions, the matrix viscosity or whether the fiber was a binary or ternary blend. To improve the properties, PP/polyaniline-complex blends were filled with CNTs. The CNTs and the polyaniline-complex both had an increasing effect on the crystallization temperature and the thermal stability of PP. Furthermore, the maximum conductivity was observed in samples containing both CNTs and polyaniline-complex rather than the PP with either one of the fillers. Although increasing the content of CNTs improved the conductivity in PP/CNT fibers, the ease of melt spinning, diameter uniformity and mechanical properties of fibers were adversely affected. Diameter variation of PP/CNT as-spun fibers was shown to be an indication of hidden melt-drawings that had occurred during the fiber extrusion; this could lead to variations in morphology such as increases in the insulating microcracks and the distance between the conductive agglomerates in the drawn parts of the fiber. Variations in morphology result in variations in the electrical conductivity; consequently, the conductivity of such inhomogeneous fiber is no longer its physical property, as this varies with varying size.

Place, publisher, year, edition, pages
Chalmers University of Technology, 2011
Series
Skrifter från Högskolan i Borås, ISSN 0280-381X ; 31
Series
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie, ISSN 0346-718X ; 3211
Keywords
conductive fibres, composites, blending, melt spinning, morphology, polyaniline, carbon nanotube, polypropylene, polyamide, draw-ratio, conductivity, Energi och material
National Category
Polymer Chemistry Materials Engineering
Identifiers
urn:nbn:se:hb:diva-3590 (URN)2320/8194 (Local ID)978-91-7385-530-3 (ISBN)2320/8194 (Archive number)2320/8194 (OAI)
Note
Thesis to be defended in public on Friday, May 20, 2011 at 10.00 at KC-salen, Kemigården 4, Göteborg, for the degree of Doctor of Philosophy.Available from: 2015-12-04 Created: 2015-12-04
Soroudi, A., Skrifvars, M. & Liu, H. (2011). Polyaniline: polypropylene melt-spun fiber filaments: The collaborative effects of blending conditions and fiber draw ratios on the electrical properties of fiber filaments. Journal of Applied Polymer Science, 119(1), 558-564
Open this publication in new window or tab >>Polyaniline: polypropylene melt-spun fiber filaments: The collaborative effects of blending conditions and fiber draw ratios on the electrical properties of fiber filaments
2011 (English)In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 119, no 1, p. 558-564Article in journal (Refereed) Published
Abstract [en]

A melt-processable polyaniline complex was blended with polypropylene under different mixing conditions and melt-spun into fiber filaments under different draw ratios. The conductivity, electrical resistance at different voltages, and morphological characteristics of the prepared fibers were investigated. The morphology of this two-phase blend was demonstrated to have a large effect on the conductivity level and the linearity of the resistance–voltage relationship of the blend fibers. Two factors had substantial effects on the morphology and electrical properties of the fibers. They were the size of the initial dispersed conductive phase, which depended on the melt blending conditions, and the stress applied to orient this phase to a fibril-like morphology, which was controlled by the draw ratio of the fiber. The two factors were shown to be associated with each other to maintain an appropriate balance of fibril formation and breakage and to create continuous conductive pathways.

Place, publisher, year, edition, pages
John Wiley & Sons, Inc., 2011
Keywords
blends, conducting polymers, drawing, fibres, morphology, Energi och material
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:hb:diva-2981 (URN)10.1002/app.32655 (DOI)2320/7355 (Local ID)2320/7355 (Archive number)2320/7355 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-12-01Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1044-5129

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