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Kolodziej L, Iwasińska-Kowalska O, Wróblewski G, Giżewski T, Jakubowska M, Lekawa-Raus A. Hydrogels and Carbon Nanotubes: Composite Electrode Materials for Long-Term Electrocardiography Monitoring. J Funct Biomater 2024; 15:113. [PMID: 38786625 PMCID: PMC11122422 DOI: 10.3390/jfb15050113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 05/25/2024] Open
Abstract
This paper presents methods for developing high-performance interface electrode materials designed to enhance signal collection efficacy during long-term (over 24 h) electrocardiography (ECG) monitoring. The electrode materials are fabricated by integrating commercial ECG liquid hydrogels with carbon nanotubes (CNTs), which are widely utilized in dry-electrode technologies and extensively discussed in the current scientific literature. The composite materials are either prepared by dispersing CNTs within the commercial liquid hydrogel matrix or by encasing the hydrogels in macroscopic CNT films. Both approaches ensure the optimal wetting of the epidermis via the hydrogels, while the CNTs reduce material impedance and stabilize the drying process. The resulting electrode materials maintain their softness, allowing for micro-conformal skin attachment, and are biocompatible. Empirical testing confirms that the ECG electrodes employing these hybrid hydrogels adhere to relevant standards for durations exceeding 24 h. These innovative hybrid solutions merge the benefits of both wet and dry ECG electrode technologies, potentially facilitating the extended monitoring of ECG signals and thus advancing the diagnosis and treatment of various cardiac conditions.
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Affiliation(s)
- Leszek Kolodziej
- Faculty of Mechatronics, Warsaw University of Technology, 02-525 Warsaw, Poland (G.W.)
| | | | - Grzegorz Wróblewski
- Faculty of Mechatronics, Warsaw University of Technology, 02-525 Warsaw, Poland (G.W.)
| | - Tomasz Giżewski
- Faculty of Electrical Engineering and Computer Science, Lublin University of Technology, 20-618 Lublin, Poland
| | - Małgorzata Jakubowska
- Faculty of Mechanical and Industrial Engineering, Warsaw University of Technology, 02-524 Warsaw, Poland;
- Centre for Advanced Materials and Technologies, Warsaw University of Technology, 02-822 Warsaw, Poland
| | - Agnieszka Lekawa-Raus
- Centre for Advanced Materials and Technologies, Warsaw University of Technology, 02-822 Warsaw, Poland
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Moslehi S, Rowland C, Smith JH, Watterson WJ, Griffiths W, Montgomery RD, Philliber S, Marlow CA, Perez MT, Taylor RP. Fractal Electronics for Stimulating and Sensing Neural Networks: Enhanced Electrical, Optical, and Cell Interaction Properties. ADVANCES IN NEUROBIOLOGY 2024; 36:849-875. [PMID: 38468067 DOI: 10.1007/978-3-031-47606-8_43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Imagine a world in which damaged parts of the body - an arm, an eye, and ultimately a region of the brain - can be replaced by artificial implants capable of restoring or even enhancing human performance. The associated improvements in the quality of human life would revolutionize the medical world and produce sweeping changes across society. In this chapter, we discuss several approaches to the fabrication of fractal electronics designed to interface with neural networks. We consider two fundamental functions - stimulating electrical signals in the neural networks and sensing the location of the signals as they pass through the network. Using experiments and simulations, we discuss the favorable electrical performances that arise from adopting fractal rather than traditional Euclidean architectures. We also demonstrate how the fractal architecture induces favorable physical interactions with the cells they interact with, including the ability to direct the growth of neurons and glia to specific regions of the neural-electronic interface.
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Affiliation(s)
- S Moslehi
- Physics Department, University of Oregon, Eugene, OR, USA
| | - C Rowland
- Physics Department, University of Oregon, Eugene, OR, USA
| | - J H Smith
- Physics Department, University of Oregon, Eugene, OR, USA
| | - W J Watterson
- Physics Department, University of Oregon, Eugene, OR, USA
| | - W Griffiths
- Physics Department, University of Oregon, Eugene, OR, USA
| | - R D Montgomery
- Physics Department, University of Oregon, Eugene, OR, USA
| | - S Philliber
- Physics Department, University of Oregon, Eugene, OR, USA
| | - C A Marlow
- Physics Department, California Polytechnic State University, San Luis Obispo, CA, USA
| | - M-T Perez
- Department of Clinical Sciences Lund, Division of Ophthalmology, Lund University, Lund, Sweden
| | - R P Taylor
- Physics Department, University of Oregon, Eugene, OR, USA.
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Abu-Saude M, Morshed BI. Inductive Coupling of Bipolar Signals with a Conjugate Coil Pair for an Analog Passive ECG Sensor Using a PPy-Coated pvCNT Dry Electrodes. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23115283. [PMID: 37300009 DOI: 10.3390/s23115283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/27/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023]
Abstract
The wireless capture of analog differential signals from fully passive (battery-less) sensors is technically challenging but it can allow for the seamless capture of differential biosignals such as an electrocardiogram (ECG). This paper presents a novel design for the wireless capture of analog differential signals using a novel conjugate coil pair for a wireless resistive analog passive (WRAP) ECG sensor. Furthermore, we integrate this sensor with a new type of dry electrode, namely conductive polymer polypyrrole (PPy)-coated patterned vertical carbon nanotube (pvCNT) electrodes. The proposed circuit uses dual-gate depletion-mode MOSFETs to convert the differential biopotential signals to correlated drain-source resistance changes and the conjugate coil wirelessly transmits the differences of the two input signals. The circuit rejects (17.24 dB) common mode signals and passing only differential signals. We have integrated this novel design with our previously reported PPy-coated pvCNT dry ECG electrodes, fabricated on a stainless steel substrate with a diameter of 10 mm, which provided a zero-power (battery-less) ECG capture system for long duration monitoring. The scanner transmits an RF carrier signal at 8.37 MHz. The proposed ECG WRAP sensor uses only two complementary biopotential amplifier circuits, each of which has a single-depletion MOSFET. The amplitude-modulated RF signal is envelope-detected, filtered, amplified, and transmitted to a computer for signal processing. ECG signals are collected using this WRAP sensor and compared with a commercial counterpart. Due to the battery-less nature of the ECG WRAP sensor, it has the potential to be a body-worn electronic circuit patch with dry pvCNT electrodes that stably operate for a long period of time.
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Affiliation(s)
- Mohammad Abu-Saude
- Department of Electrical and Computer Engineering, University of Memphis, Memphis, TN 38152, USA
| | - Bashir I Morshed
- Department of Computer Science, Texas Tech University, Lubbock, TX 79409, USA
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McCrae P, Spong H, Rutherford AA, Osborne V, Mahnam A, Pearson W. A Smart Textile Band Achieves High-Quality Electrocardiograms in Unrestrained Horses. Animals (Basel) 2022; 12:ani12233254. [PMID: 36496775 PMCID: PMC9740902 DOI: 10.3390/ani12233254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/16/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Electrocardiography (ECG) is an essential tool in assessing equine health and fitness. However, standard ECG devices are expensive and rely on the use of adhesive electrodes, which may become detached and are associated with reduced ECG quality over time. Smart textile electrodes composed of stainless-steel fibers have previously been shown to be a suitable alternative in horses at rest and during exercise. The objective of this study was to compare ECG quality using a smart textile girth band knit with silver and carbon yarns to standard adhesive silver/silver chloride (Ag/AgCl) electrodes. Simultaneous three-lead ECGs were recorded using a smart textile band and Ag/AgCl electrodes in 22 healthy, mixed-breed horses that were unrestrained in stalls. ECGs were compared using the following quality metrics: Kurtosis (k) value, Kurtosis signal quality index (kSQI), percentage of motion artifacts (%MA), peak signal amplitude, and heart rate (HR). Two-way ANOVA with Tukey’s multiple comparison tests was conducted to compare each metric. No significant differences were found in any of the assessed metrics between the smart textile band and Ag/AgCl electrodes, with the exception of peak amplitude. Kurtosis and kSQI values were excellent for both methods (textile mean k = 21.8 ± 6.1, median kSQI = 0.98 [0.92−1.0]; Ag/AgCl k = 21.2 ± 7.6, kSQI = 0.99 [0.97−1.0]) with <0.5% (<1 min) of the recording being corrupted by MAs for both. This study demonstrates that smart textiles are a practical and reliable alternative to the standard electrodes typically used in ECG monitoring of horses.
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Affiliation(s)
- Persephone McCrae
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Hannah Spong
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | | | - Vern Osborne
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Amin Mahnam
- Department of Research and Development, Myant Inc., Toronto, ON M9W 1B6, Canada
| | - Wendy Pearson
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
- Correspondence:
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Zhang M, Guo N, Gao Q, Li H, Wang Z. Design, Characterization, and Performance of Woven Fabric Electrodes for Electrocardiogram Signal Monitoring. SENSORS 2022; 22:s22155472. [PMID: 35897976 PMCID: PMC9331634 DOI: 10.3390/s22155472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/16/2022] [Accepted: 07/18/2022] [Indexed: 11/20/2022]
Abstract
Conductive gel needs to be applied between the skin and standard medical electrodes when monitoring electrocardiogram (ECG) signals, but this can cause skin irritation, particularly during long-term monitoring. Fabric electrodes are flexible, breathable, and capable of sensing ECG signals without conductive gel. The objective of this study was to design and fabricate a circular fabric electrode using weaving technology. To optimize the woven fabric electrode, electrodes of different diameter, fabric weave, and weft density were devised, and the AC impedance, open-circuit voltage, and static ECG signal were measured and comprehensively evaluated. Diameter of 4 cm, 12/5 sateen, and weft density of 46 picks/cm were concluded as the appropriate parameters of the fabric electrode. ECG signals in swinging, squatting, and rotating states were compared between the woven fabric electrode and the standard medical electrode. The results showed that the characteristic waveform of the woven fabric electrode with 86.7% improved data was more obvious than that of the standard medical electrode. This work provides reference data that will be helpful for commercializing the integration of fabric electrodes into smart textiles.
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Affiliation(s)
- Meiling Zhang
- School of Textile Science and Engineering, Tiangong University, Tianjin 300387, China; (M.Z.); (N.G.); (Q.G.)
| | - Ningting Guo
- School of Textile Science and Engineering, Tiangong University, Tianjin 300387, China; (M.Z.); (N.G.); (Q.G.)
| | - Qian Gao
- School of Textile Science and Engineering, Tiangong University, Tianjin 300387, China; (M.Z.); (N.G.); (Q.G.)
| | - Hongqiang Li
- School of Electronic and Information Engineering, Tiangong University, Tianjin 300387, China;
| | - Zhangang Wang
- School of Software, Tiangong University, Tianjin 300387, China
- Correspondence:
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Moslehi S, Rowland C, Smith JH, Watterson WJ, Miller D, Niell CM, Alemán BJ, Perez MT, Taylor RP. Controlled assembly of retinal cells on fractal and Euclidean electrodes. PLoS One 2022; 17:e0265685. [PMID: 35385490 PMCID: PMC8985931 DOI: 10.1371/journal.pone.0265685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 03/04/2022] [Indexed: 11/25/2022] Open
Abstract
Controlled assembly of retinal cells on artificial surfaces is important for fundamental cell research and medical applications. We investigate fractal electrodes with branches of vertically-aligned carbon nanotubes and silicon dioxide gaps between the branches that form repeating patterns spanning from micro- to milli-meters, along with single-scaled Euclidean electrodes. Fluorescence and electron microscopy show neurons adhere in large numbers to branches while glial cells cover the gaps. This ensures neurons will be close to the electrodes’ stimulating electric fields in applications. Furthermore, glia won’t hinder neuron-branch interactions but will be sufficiently close for neurons to benefit from the glia’s life-supporting functions. This cell ‘herding’ is adjusted using the fractal electrode’s dimension and number of repeating levels. We explain how this tuning facilitates substantial glial coverage in the gaps which fuels neural networks with small-world structural characteristics. The large branch-gap interface then allows these networks to connect to the neuron-rich branches.
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Affiliation(s)
- Saba Moslehi
- Physics Department, University of Oregon, Eugene, Oregon, United States of America
- Materials Science Institute, University of Oregon, Eugene, Oregon, United States of America
| | - Conor Rowland
- Physics Department, University of Oregon, Eugene, Oregon, United States of America
- Materials Science Institute, University of Oregon, Eugene, Oregon, United States of America
| | - Julian H. Smith
- Physics Department, University of Oregon, Eugene, Oregon, United States of America
- Materials Science Institute, University of Oregon, Eugene, Oregon, United States of America
| | - William J. Watterson
- Physics Department, University of Oregon, Eugene, Oregon, United States of America
- Materials Science Institute, University of Oregon, Eugene, Oregon, United States of America
| | - David Miller
- Physics Department, University of Oregon, Eugene, Oregon, United States of America
- Materials Science Institute, University of Oregon, Eugene, Oregon, United States of America
- Oregon Center for Optical, Molecular and Quantum Science, University of Oregon, Eugene, Oregon, United States of America
| | - Cristopher M. Niell
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States of America
- Department of Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Benjamín J. Alemán
- Physics Department, University of Oregon, Eugene, Oregon, United States of America
- Materials Science Institute, University of Oregon, Eugene, Oregon, United States of America
- Oregon Center for Optical, Molecular and Quantum Science, University of Oregon, Eugene, Oregon, United States of America
- Phil and Penny Knight Campus for Accelerating Scientific Impact, University of Oregon, Eugene, Oregon, United States of America
| | - Maria-Thereza Perez
- Division of Ophthalmology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
- NanoLund, Lund University, Lund, Sweden
- * E-mail: (RPT); (MTP)
| | - Richard P. Taylor
- Physics Department, University of Oregon, Eugene, Oregon, United States of America
- Materials Science Institute, University of Oregon, Eugene, Oregon, United States of America
- Phil and Penny Knight Campus for Accelerating Scientific Impact, University of Oregon, Eugene, Oregon, United States of America
- * E-mail: (RPT); (MTP)
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Nigusse AB, Mengistie DA, Malengier B, Tseghai GB, Langenhove LV. Wearable Smart Textiles for Long-Term Electrocardiography Monitoring-A Review. SENSORS 2021; 21:s21124174. [PMID: 34204577 PMCID: PMC8234162 DOI: 10.3390/s21124174] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/11/2021] [Accepted: 06/14/2021] [Indexed: 12/28/2022]
Abstract
The continuous and long-term measurement and monitoring of physiological signals such as electrocardiography (ECG) are very important for the early detection and treatment of heart disorders at an early stage prior to a serious condition occurring. The increasing demand for the continuous monitoring of the ECG signal needs the rapid development of wearable electronic technology. During wearable ECG monitoring, the electrodes are the main components that affect the signal quality and comfort of the user. This review assesses the application of textile electrodes for ECG monitoring from the fundamentals to the latest developments and prospects for their future fate. The fabrication techniques of textile electrodes and their performance in terms of skin–electrode contact impedance, motion artifacts and signal quality are also reviewed and discussed. Textile electrodes can be fabricated by integrating thin metal fiber during the manufacturing stage of textile products or by coating textiles with conductive materials like metal inks, carbon materials, or conductive polymers. The review also discusses how textile electrodes for ECG function via direct skin contact or via a non-contact capacitive coupling. Finally, the current intensive and promising research towards finding textile-based ECG electrodes with better comfort and signal quality in the fields of textile, material, medical and electrical engineering are presented as a perspective.
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Affiliation(s)
- Abreha Bayrau Nigusse
- Department of Materials, Textiles and Chemical Engineering, Ghent University, 9000 Gent, Belgium; (B.M.); (G.B.T.); (L.V.L.)
- Ethiopian Institute of Textile and Fashion Technology, Bahir Dar University, Bahir Dar 6000, Ethiopia;
- Correspondence: ; Tel.: +32-465-66-8911
| | - Desalegn Alemu Mengistie
- Ethiopian Institute of Textile and Fashion Technology, Bahir Dar University, Bahir Dar 6000, Ethiopia;
- Materials Engineering Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Benny Malengier
- Department of Materials, Textiles and Chemical Engineering, Ghent University, 9000 Gent, Belgium; (B.M.); (G.B.T.); (L.V.L.)
| | - Granch Berhe Tseghai
- Department of Materials, Textiles and Chemical Engineering, Ghent University, 9000 Gent, Belgium; (B.M.); (G.B.T.); (L.V.L.)
| | - Lieva Van Langenhove
- Department of Materials, Textiles and Chemical Engineering, Ghent University, 9000 Gent, Belgium; (B.M.); (G.B.T.); (L.V.L.)
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Kolanowska A, Herman AP, Jędrysiak RG, Boncel S. Carbon nanotube materials for electrocardiography. RSC Adv 2021; 11:3020-3042. [PMID: 35424207 PMCID: PMC8693996 DOI: 10.1039/d0ra08679g] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/07/2021] [Indexed: 01/09/2023] Open
Abstract
Carbon nanotubes (CNTs) as 1D nanomaterials of excellent physicochemical characteristics bring hope to compete and eventually conquer traditional solutions in electrocardiography - one of the most powerful and non-invasive diagnostic tools in cardiac disorders. Our review tracks (from 2008) the development of CNTs as critical components in the systems where CNTs serve mainly as electroconductive fillers hence enable recording electrocardiographs (ECG). The characteristics of the CNT-based ECG systems - mainly to-skin electrodes and in a few cases wiring - covers their electrical and mechanical performance (adhesivity, flexibility, elasticity) and qualitative biocompatibility. By comprehensive analysis of the state-of-art in this field, we intend to indicate the most important challenges for the CNT (and other) materials to be applied in scale-up solution for electrocardiography in the near future.
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Affiliation(s)
- Anna Kolanowska
- Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, NanoCarbon Group Bolesława Krzywoustego 4 44-100 Gliwice Poland +48 32 237 20 94 +48 32 237 12 72
| | - Artur P Herman
- Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, NanoCarbon Group Bolesława Krzywoustego 4 44-100 Gliwice Poland +48 32 237 20 94 +48 32 237 12 72
- Department of Semiconductor Materials Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology Wybrzeże Wyspiańskiego 27 50-370 Wrocław Poland
| | - Rafał G Jędrysiak
- Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, NanoCarbon Group Bolesława Krzywoustego 4 44-100 Gliwice Poland +48 32 237 20 94 +48 32 237 12 72
| | - Sławomir Boncel
- Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, NanoCarbon Group Bolesława Krzywoustego 4 44-100 Gliwice Poland +48 32 237 20 94 +48 32 237 12 72
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