Evaluation of Bipolar, Tripolar, and Quadripolar Laplacian Estimates of Electrocardiogram via Concentric Ring Electrodes

[EN] Surface Laplacian estimates via concentric ring electrodes (CREs) have proven to enhance spatial resolution compared to conventional disc electrodes, which is of great importance for P-wave analysis. In this study, Laplacian estimates for traditional bipolar configuration (BC), two tripolar configurations with linearly decreasing and increasing inter-ring distances (TCLDIRD and TCLIIRD, respectively), and quadripolar configuration (QC) were obtained from cardiac recordings with pentapolar CREs placed at CMV1 and CMV2 positions. Normalized P-wave amplitude (NAP) was computed to assess the contrast to study atrial activity. Signals were of good quality (20-30 dB). Atrial activity was more emphasized at CMV1 (NAP similar or equal to 0.19-0.24) compared to CMV2 (NAP similar or equal to 0.08-0.10). Enhanced spatial resolution of TCLIIRD and QC resulted in higher NAP values than BC and TCLDIRD. Comparison with simultaneous standard 12-lead ECG proved that Laplacian estimates at CMV1 outperformed all the limb and chest standard leads in the contrast to study P-waves. Clinical recordings with CRE at this position could allow more detailed observation of atrial activity and facilitate the diagnosis of associated pathologies. Furthermore, such recordings would not require additional electrodes on limbs and could be performed wirelessly, so it should also be suitable for ambulatory monitoring, for example, using cardiac Holter monitors.This research was funded by the National Science Foundation (NSF) Division of Human Resource Development (HRD) Tribal Colleges and Universities Program (TCUP), grants number 1622481 and 1914787 to O.M.Garcia-Casado, J.; Ye Lin, Y.; Prats-Boluda, G.; Makeyev, O. (2019). Evaluation of Bipolar, Tripolar, and Quadripolar Laplacian Estimates of Electrocardiogram via Concentric Ring Electrodes. Sensors. 19(17):1-11. https://doi.org/10.3390/s19173780S1111917Roth, G. A., Johnson, C., Abajobir, A., Abd-Allah, F., Abera, S. F., Abyu, G., … Alam, K. (2017). Global, Regional, and National Burden of Cardiovascular Diseases for 10 Causes, 1990 to 2015. Journal of the American College of Cardiology, 70(1), 1-25. doi:10.1016/j.jacc.2017.04.052Lopez, A. D., Mathers, C. D., Ezzati, M., Jamison, D. T., & Murray, C. J. (2006). Global and regional burden of disease and risk factors, 2001: systematic analysis of population health data. The Lancet, 367(9524), 1747-1757. doi:10.1016/s0140-6736(06)68770-9Bhatnagar, P., Wickramasinghe, K., Wilkins, E., & Townsend, N. (2016). Trends in the epidemiology of cardiovascular disease in the UK. Heart, 102(24), 1945-1952. doi:10.1136/heartjnl-2016-309573https://healthmetrics.heart.org/cardiovascular-disease-a-costly-burden/Leal, J., Luengo-Fernández, R., Gray, A., Petersen, S., & Rayner, M. (2006). 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Body surface Laplacian ECG mapping. IEEE Transactions on Biomedical Engineering, 39(11), 1179-1191. doi:10.1109/10.168684He, B., & Cohen, R. J. (1995). Body Surface Laplacian Electrocardiographic Mapping−A Review. Critical Reviews in Biomedical Engineering, 23(5-6), 475-510. doi:10.1615/critrevbiomedeng.v23.i5-6.30UMETANI, K., OKAMOTO, Y., MASHIMA, S., ONO, K., HOSAKA, H., & HE, B. (1998). Body Surface Laplacian Mapping in Patients with Left or Right Ventricular Bundle Branch Block. Pacing and Clinical Electrophysiology, 21(11), 2043-2054. doi:10.1111/j.1540-8159.1998.tb01122.xBin He, Guanglin Li, & Jie Lian. (2002). A spline Laplacian ECG estimator in a realistic geometry volume conductor. IEEE Transactions on Biomedical Engineering, 49(2), 110-117. doi:10.1109/10.979350Besio, G., Koka, K., Aakula, R., & Weizhong Dai. (2006). Tri-polar concentric ring electrode development for Laplacian electroencephalography. IEEE Transactions on Biomedical Engineering, 53(5), 926-933. doi:10.1109/tbme.2005.863887Besio, W., Aakula, R., Koka, K., & Dai, W. (2006). Development of a Tri-polar Concentric Ring Electrode for Acquiring Accurate Laplacian Body Surface Potentials. Annals of Biomedical Engineering, 34(3), 426-435. doi:10.1007/s10439-005-9054-8Besio, W., & Chen, T. (2007). Tripolar Laplacian electrocardiogram and moment of activation isochronal mapping. Physiological Measurement, 28(5), 515-529. doi:10.1088/0967-3334/28/5/006Prats-Boluda, G., Garcia-Casado, J., Martinez-de-Juan, J. L., & Ye-Lin, Y. (2011). Active concentric ring electrode for non-invasive detection of intestinal myoelectric signals. Medical Engineering & Physics, 33(4), 446-455. doi:10.1016/j.medengphy.2010.11.009Prats-Boluda, G., Ye-Lin, Y., Bueno-Barrachina, J., Rodriguez de Sanabria, R., & Garcia-Casado, J. (2016). Towards the clinical use of concentric electrodes in ECG recordings: influence of ring dimensions and electrode position. Measurement Science and Technology, 27(2), 025705. doi:10.1088/0957-0233/27/2/025705Zena-Giménez, V., Garcia-Casado, J., Ye-Lin, Y., Garcia-Breijo, E., & Prats-Boluda, G. (2018). A Flexible Multiring Concentric Electrode for Non-Invasive Identification of Intestinal Slow Waves. Sensors, 18(2), 396. doi:10.3390/s18020396Ye-Lin, Y., Alberola-Rubio, J., Prats-boluda, G., Perales, A., Desantes, D., & Garcia-Casado, J. (2014). Feasibility and Analysis of Bipolar Concentric Recording of Electrohysterogram with Flexible Active Electrode. Annals of Biomedical Engineering, 43(4), 968-976. doi:10.1007/s10439-014-1130-5Wang, K., Parekh, U., Pailla, T., Garudadri, H., Gilja, V., & Ng, T. N. (2017). Stretchable Dry Electrodes with Concentric Ring Geometry for Enhancing Spatial Resolution in Electrophysiology. Advanced Healthcare Materials, 6(19), 1700552. doi:10.1002/adhm.201700552Lidón-Roger, J., Prats-Boluda, G., Ye-Lin, Y., Garcia-Casado, J., & Garcia-Breijo, E. (2018). Textile Concentric Ring Electrodes for ECG Recording Based on Screen-Printing Technology. Sensors, 18(1), 300. doi:10.3390/s18010300Makeyev, O., Ding, Q., & Besio, W. G. (2016). Improving the accuracy of Laplacian estimation with novel multipolar concentric ring electrodes. Measurement, 80, 44-52. doi:10.1016/j.measurement.2015.11.017Makeyev, O., & Besio, W. (2016). Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes. Sensors, 16(6), 858. doi:10.3390/s16060858Makeyev, O. (2018). Solving the general inter-ring distances optimization problem for concentric ring electrodes to improve Laplacian estimation. BioMedical Engineering OnLine, 17(1). doi:10.1186/s12938-018-0549-6Ye-Lin, Y., Bueno-Barrachina, J. M., Prats-boluda, G., Rodriguez de Sanabria, R., & Garcia-Casado, J. (2017). Wireless sensor node for non-invasive high precision electrocardiographic signal acquisition based on a multi-ring electrode. Measurement, 97, 195-202. doi:10.1016/j.measurement.2016.11.009Prats-Boluda, G., Ye-Lin, Y., Pradas-Novella, F., Garcia-Breijo, E., & Garcia-Casado, J. (2018). Textile Concentric Ring Electrodes: Influence of Position and Electrode Size on Cardiac Activity Monitoring. Journal of Sensors, 2018, 1-9. doi:10.1155/2018/7290867Huiskamp, G. (1991). Difference formulas for the surface Laplacian on a triangulated surface. Journal of Computational Physics, 95(2), 477-496. doi:10.1016/0021-9991(91)90286-tHamilton, P. S., & Tompkins, W. J. (1986). Quantitative Investigation of QRS Detection Rules Using the MIT/BIH Arrhythmia Database. IEEE Transactions on Biomedical Engineering, BME-33(12), 1157-1165. doi:10.1109/tbme.1986.325695Koka, K., & Besio, W. G. (2007). Improvement of spatial selectivity and decrease of mutual information of tri-polar concentric ring electrodes. Journal of Neuroscience Methods, 165(2), 216-222. doi:10.1016/j.jneumeth.2007.06.007Prats-Boluda, G., Ye-Lin, Y., Bueno Barrachina, J. M., Senent, E., Rodriguez de Sanabria, R., & Garcia-Casado, J. (2015). Development of a portable wireless system for bipolar concentric ECG recording. Measurement Science and Technology, 26(7), 075102. doi:10.1088/0957-0233/26/7/07510

Enhancement of Non-Invasive Recording of Electroenterogram by Means of a Flexible Array of Concentric Ring Electrodes

Monitoring intestinal myoelectrical activity by electroenterogram (EEnG) would be of great clinical interest for diagnosing gastrointestinal pathologies and disorders. However, surface EEnG recordings are of very low amplitude and can be severely affected by baseline drifts and respiratory and electrocardiographic (ECG) interference. In this work, a flexible array of concentric ring electrodes was developed and tested to determine whether it can provide surface EEnG signals of better quality than bipolar recordings from conventional disc electrodes. With this aime, sixteen healthy subjects in a fasting state (>8h) underwent recording. The capabiltiy of detecting intestinal pacemaker activity (slow wave) and the influence of physiological interferences were studied. The signals obtained from the concentric ring electrodes proved to be more robust to ECG and respiratory interference than those from conventional disc electrodes. The results also show that intestinal EEnG components such as the slow wave can be more easily identified by the proposed system based on a flexible array of concentric ring electrodes. The developed active electrode array could be a very valuable tool for non-invasive diagnosis of disease states such as ischemia and motility disorders of the small bowel which are known to alter the normal enteric slow wave activity.Research supported in part by the Ministerio de Ciencia y Tecnologia de Espana (TEC 2010-16945). The proof-reading of this paper was funded by the Universitat Politecnica de Valencia, Spain.Garcia Casado, FJ.; Zena Giménez, VF.; Prats Boluda, G.; Ye Lin, Y. (2014). Enhancement of Non-Invasive Recording of Electroenterogram by Means of a Flexible Array of Concentric Ring Electrodes. Annals of Biomedical Engineering. 42(3):651-660. https://doi.org/10.1007/s10439-013-0935-yS651660423Abo, M., J. Liang, L. Qian, and J. D. Chen. 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Análisis del uso del póster científico y de la revisión por pares como herramienta desarrollo de la competencia comunicación efectiva en estudiantes de grado en ingeniería

[EN] Today’s society requires graduates who present a wide range of cross skills in addition to master the specific skills of their grade, as in the case of effective communication skill. In this paper the use of scientific-technical poster as a communication tool for undergraduate engineering students is studied, analyzing whether peer review teaching strategy can improve the students’ writing-visual communication skills. Additionally, the burden associated with the use of this strategy and the students’ degree of acceptance is studied. Experimental results indicate that both students and teachers have positively assessed the use of the scientific-technical poster as an effective tool for developing the students’ communication skills. Furthermore, peer review process has identified numerous common errors in the posters made by the students, improving their skill development without excessive additional burden. 92.3% of the surveyed students consider that peer review is a good teaching strategy for developing communication skills and it should be extended to other subjects and/or courses.[ES] La sociedad actual requiere de egresados que además de dominar las competencias específicas de su título presenten un amplio abanico de competencias transversales como es el caso de la comunicación efectiva. En el presente trabajo se valora el uso del póster científico-técnico como herramienta de comunicación para los alumnos de grado en ingeniería, analizando si el empleo de la revisión por pares permite a los estudiantes mejorar esta competencia. Asimismo se valora el grado de aceptación de esta metodología por parte del alumnado y si supone una carga adicional excesiva o no. Los resultados de la experiencia indican que tanto el alumnado como el profesorado valoran positivamente el desarrollo y defensa de un póster científico–técnico como herramienta de trabajo de la competencia comunicación efectiva. Además se evidencia que el proceso de la revisión por pares ha permitido identificar un gran número de errores presentes en los pósteres elaborados por los alumnos, ayudándoles a una mejor adhesión de la competencia, sin suponer una carga adicional excesiva.El 92.3% de los alumnos encuestados de la asignatura opinan que es una buena herramienta docente que debería emplearse en otras asignaturas y/o cursos.Prats Boluda, G.; Ye Lin, Y.; Trénor Gomis, BA. (2016). Análisis del uso del póster científico y de la revisión por pares como herramienta desarrollo de la competencia comunicación efectiva en estudiantes de grado en ingeniería. En In-Red 2016. II Congreso nacional de innovación educativa y docencia en red. Editorial Universitat Politècnica de València. https://doi.org/10.4995/INRED2016.2016.4381OC

Aplicación de la Clase Inversa en la Enseñanza de la Electrónica Analógica en un Grupo de Alto Rendimiento Académico

[EN] The need of increasing the participation of the student in the teaching and learning process at University has led to the concept of flip teaching. This methodology is characterized by the fact that the student works on the theoretical concepts independently and using mainly audiovisual materials. Later, the student works on applied activities in the teaching room under the teacher supervision, in order to reinforce his learning. The objective of the present study is to evaluate the impact of flip teaching in analog electronics in the Degree of Engineering in Electronics and Automatics. This methodology has been applied during the academic years 2014-2015, 2015- 2016, and 2016-2017 in the group of high academic performance (ARA group), in which English is the medium of instruction. 95% of our students considered that flip teaching was a very adecuate methodology for the teaching and learning process of this course. Furthermore, the evaluation methods based on the tool SOCRATIVE have been positevely accepted. Finally, the academic performance was higher in the ARA group with respect to the rest of the groups, which did not happen in previous years when no flip teaching was applied at all.[ES] De la necesidad de una mayor participación del alumnado universitario en el proceso de enseñanza-aprendizaje ha surgido el concepto de la docencia inversa. Mediante el uso de esta metodología, el alumno trabaja, de manera independiente, los conceptos más teóricos, con la ayuda de material audiovisual principalmente. Posteriormente, en clase, el alumno realiza actividades más prácticas dirigidas por el profesor y así afianza los conceptos aprendidos. El objetivo del presente trabajo es evaluar el impacto de dicha metodología en la enseñanza de la electrónica analógica en la titulación de Grado en Ingeniería Electrónica y Automática. Se ha aplicado la docencia inversa en los cursos 2014-2015, 2015-2016 y 2016-2017 en el grupo de alto rendimiento académico, que cursa la asignatura en inglés. La valoración del alumnado ha sido muy positiva: un 95% del alumnado considera muy adecuada la metodología. Además, los métodos de evaluación mediante el uso de la herramienta SOCRATIVE se han valorado positivamente y el rendimiento académico del grupo ARA ha mejorado con respecto a los demás grupos, lo cual no sucedió en años anteriores cuando no se aplicaba la docencia inversa.Trénor Gomis, BA.; Prats Boluda, G.; Ye Lin, Y. (2017). Aplicación de la Clase Inversa en la Enseñanza de la Electrónica Analógica en un Grupo de Alto Rendimiento Académico. En In-Red 2017. III Congreso Nacional de innovación educativa y de docencia en red. Editorial Universitat Politècnica de València. 517-528. https://doi.org/10.4995/INRED2017.2017.6842OCS51752

Assessment of Muscle Coordination Changes Caused by the Use of an Occupational Passive Lumbar Exoskeleton in Laboratory Conditions

[EN] The introduction of exoskeletons in industry has focused on improving worker safety. Exoskeletons have the objective of decreasing the risk of injury or fatigue when performing physically demanding tasks. Exoskeletons' effect on the muscles is one of the most common focuses of their assessment. The present study aimed to analyze the muscle interactions generated during load-handling tasks in laboratory conditions with and without a passive lumbar exoskeleton. The electromyographic data of the muscles involved in the task were recorded from twelve participants performing load-handling tasks. The correlation coefficient, coherence coefficient, mutual information, and multivariate sample entropy were calculated to determine if there were significant differences in muscle interactions between the two test conditions. The results showed that muscle coordination was affected by the use of the exoskeleton. In some cases, the exoskeleton prevented changes in muscle coordination throughout the execution of the task, suggesting a more stable strategy. Additionally, according to the directed Granger causality, a trend of increasing bottom-up activation was found throughout the task when the participant was not using the exoskeleton. Among the different variables analyzed for coordination, the most sensitive to changes was the multivariate sample entropy.This study was funded by Fundación Prevent.Iranzo-Egea, S.; Belda-Lois, J.; Martínez-De-Juan, JL.; Prats-Boluda, G. (2023). Assessment of Muscle Coordination Changes Caused by the Use of an Occupational Passive Lumbar Exoskeleton in Laboratory Conditions. Sensors. 23(24):1-14. https://doi.org/10.3390/s23249631114232

Validating the Comparison Framework for the Finite Dimensions Model of Concentric Ring Electrodes Using Human Electrocardiogram Data

[EN] While progress has been made in design optimization of concentric ring electrodes maximizing the accuracy of the surface Laplacian estimation, it was based exclusively on the negligible dimensions model of the electrode. Recent proof of concept of the new finite dimensions model that adds the radius of the central disc and the widths of concentric rings to the previously included number of rings and inter-ring distances provides an opportunity for more comprehensive design optimization. In this study, the aforementioned proof of concept was developed into a framework allowing direct comparison of any two concentric ring electrodes of the same size and with the same number of rings. The proposed framework is illustrated on constant and linearly increasing inter-ring distances tripolar concentric ring electrode configurations and validated on electrocardiograms from 20 human volunteers. In particular, ratios of truncation term coefficients between the two electrode configurations were used to demonstrate the similarity between the negligible and the finite dimension models analytically (p = 0.077). Laplacian estimates based on the two models were calculated on electrocardiogram data for emulation of linearly increasing inter-ring distances tripolar concentric ring electrode. The difference between the estimates was not statistically significant (p >> 0.05) which is consistent with the analytic result.This research was funded by the National Science Foundation (NSF) Division of Human Resource Development (HRD) Tribal Colleges and Universities Program (TCUP), grants number 1622481 and 1914787 to Oleksandr Makeyev. The authors would like to thank Rafael Rodriguez de Sanabria for his help with the human ECG data collection and Eduardo Garcia-Breijo for his help with the CRE implementation.Makeyev, O.; Musngi, M.; Moore, L.; Ye Lin, Y.; Prats-Boluda, G.; Garcia-Casado, J. 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Identification of atrial fibrillation drivers by means of concentric ring electrodes

The prevalence of atrial fibrillation (AF) has tripled in the last 50 years due to population aging. High-frequency (DFdriver) activated atrial regions lead the activation of the rest of the atria, disrupting the propagation wavefront. Fourier based spectral analysis of body surface potential maps have been proposed for DFdriver identification, although these approaches present serious drawbacks due to their limited spectral resolution for short AF epochs and the blurring effect of the volume conductor. Laplacian signals (BC-ECG) from bipolar concentric ring electrodes (CRE) have been shown to outperform the spatial resolution achieved with conventional unipolar recordings. Our aimed was to determine the best DFdriver estimator in endocardial electrograms and to assess the BC-ECG capacity of CRE to quantify AF activity non-invasively

A Surface Electromyogram Evaluation of the Postural Freedom Effects in Laparoscopic Surgery

[EN] It has been demonstrated that laparoscopic procedures benefit patients in terms of recovery time, exposure to infections and trauma. Nevertheless, it increases the number of problems for the surgeons, including the frequency and duration of awkward postures for surgeons. The repetition of these movements is considered the main cause for musculoskeletal disorders in surgeons' upper limbs. The goal of this study is to evaluate the muscular activity and muscular fatigue effect produced by both, a conventional instrument and an instrument provided with the Postural Freedom (PF) feature; which consists in a ball socket articulation that allows a variable handle-to-shaft angle, on a conventional laparoscopic pistol-grip handle. Seventeen participants were evaluated during a static simulation using both instruments. Surface electromyography was used to compare the instruments in terms of muscular activity in each target position and muscular fatigue produced in the muscles trapezius, deltoids, biceps, and flexor carpi radialis. Trapezius and deltoids were the muscles most affected. Entrance and exit targets and targets facing the participants showed the higher muscular activity values. The PF prototype reduced muscular activity in all the muscles and in the majority of the target positions showing a reduction greater than 70% of the activity required by the trapezius and deltoid muscles in comparison to the conventional tool. Muscular fatigue was produced by both instruments but it presented lower frequency values with PF prototype. The results indicated that the use of conventional instruments impacts negatively on muscular activity during laparoscopic procedures, in terms of positions adopted. The PF feature in laparoscopic instrumentation reduced the muscular activity and also decreased the signals of muscular fatigue in the muscles evaluated in comparison with the conventional tool.Pace-Bedetti, HM.; Martínez-De-Juan, JL.; Conejero Rodilla, A.; Prats-Boluda, G. (2019). A Surface Electromyogram Evaluation of the Postural Freedom Effects in Laparoscopic Surgery. IEEE. 3143-3146. https://doi.org/10.1109/EMBC.2019.88579193143314

A comparative analysis of printing techniques by using an active concentric ring electrode for bioelectrical recording

Purpose This paper aims to present a comparison between three types of manufacturing techniques, namely, screen-printed, inkjet and gravure, using different types of inks, for the implementation of concentric ring electrodes which permit estimation of Laplacian potential on the body surface. Design/methodology/approach Flexible concentric ring electrodes not only present lower skin electrode contact impedance and lower baseline wander than rigid electrodes but are also less sensitive to interference and motion artefacts. The above three techniques allow printing of conductive inks on flexible substrates, and with this work, the authors aim to study which is the best technique and ink to obtain the best electrode response. Findings From the results obtained regarding ink thickness, resistivity, electrode resistance and other performance parameters derived from electrocardiographic signal recording tests, it can be said that concentric electrodes using the screen-printing and inkjet techniques are suitable for non-invasive bioelectric signal acquisition. Originality/value The development of new types of inks and substrates for the electronics industry and the adaptation of new manufacturing techniques allow for an improvement in the development of electrodes and sensors.This work was financially supported by the Spanish Government and European FEDER funds (MAT2012-38429-C04-04).García Breijo, E.; Prats Boluda, G.; Lidon-Roger, JV.; Ye Lin, Y.; Garcia Casado, FJ. (2015). A comparative analysis of printing techniques by using an active concentric ring electrode for bioelectrical recording. Microelectronics International. 32(2):103-107. https://doi.org/10.1108/MI-03-2015-0021S103107322Besio, W., Aakula, R., Koka, K., & Dai, W. (2006). Development of a Tri-polar Concentric Ring Electrode for Acquiring Accurate Laplacian Body Surface Potentials. Annals of Biomedical Engineering, 34(3), 426-435. doi:10.1007/s10439-005-9054-8Besio, W., & Chen, T. (2007). Tripolar Laplacian electrocardiogram and moment of activation isochronal mapping. Physiological Measurement, 28(5), 515-529. doi:10.1088/0967-3334/28/5/006He, B., & Cohen, R. J. (1992). Body surface Laplacian mapping of cardiac electrical activity. The American Journal of Cardiology, 70(20), 1617-1620. doi:10.1016/0002-9149(92)90471-aLu, C.C. and Tarjan, P.P. (2002), “An ultra-high common-mode rejection ratio (CMRR) AC instrumentation amplifier for laplacian electrocardiographic measurement”,Biomedical Instrumentation and Technology, Vol. 33 No. 1, pp. 76-83.Prats-Boluda, G. , Ye-Lin, Y. , Garcia-Breijo, E. , Ibanez, J. and Garcia-Casado, J. (2012), “Active flexible concentric ring electrode for non-invasive surface bioelectrical recordings”,Measurement Science & Technology, Vol. 23 No. 12

A Flexible Multiring Concentric Electrode for Non-Invasive Identification of Intestinal Slow Waves

[EN] Developing new types of optimized electrodes for specific biomedical applications can substantially improve the quality of the sensed signals. Concentric ring electrodes have been shown to provide enhanced spatial resolution to that of conventional disc electrodes. A sensor with different electrode sizes and configurations (monopolar, bipolar, etc.) that provides simultaneous records would be very helpful for studying the best signal-sensing arrangement. A 5-pole electrode with an inner disc and four concentric rings of different sizes was developed and tested on surface intestinal myoelectrical recordings from healthy humans. For good adaptation to a curved body surface, the electrode was screen-printed onto a flexible polyester substrate. To facilitate clinical use, it is self-adhesive, incorporates a single connector and can perform dry or wet (with gel) recordings. The results show it to be a versatile electrode that can evaluate the optimal configuration for the identification of the intestinal slow wave and reject undesired interference. A bipolar concentric record with an outer ring diameter of 30 mm, a foam-free adhesive material, and electrolytic gel gave the best results.Grant from the Ministerio de Economia y Competitividad y del Fondo Europeo de Desarrollo Regional. DPI2015-68397-R (MINECO/FEDER).Zena-Giménez, VF.; Garcia Casado, FJ.; Ye Lin, Y.; Garcia-Breijo, E.; Prats-Boluda, G. (2018). A Flexible Multiring Concentric Electrode for Non-Invasive Identification of Intestinal Slow Waves. Sensors. 18(2):396-412. https://doi.org/10.3390/s18020396S39641218