| 1. |
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| 2. |
- Marquez, Juan Carlos, 1976-, et al.
(författare)
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Textile electrode straps for wrist-to-ankle bioimpedance measurements for Body Composition Analysis : Initial validation & experimental results
- 2010
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Ingår i: 2010 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC). - : IEEE Engineering in Medicine and Biology Society. - 9781424441235 ; 2010, s. 6385-8
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Konferensbidrag (refereegranskat)abstract
- Electrical Bioimpedance (EBI) is one of the non-invasive monitoring technologies that could benefit from the emerging textile based measurement systems. If reliable and reproducible EBI measurements could be done with textile electrodes, that would facilitate the utilization of EBI-based personalized healthcare monitoring applications. In this work the performance of a custom-made dry-textile electrode prototype is tested. Four-electrodes ankle-to-wrist EBI measurements have been taken on healthy subjects with the Impedimed spectrometer SFB7 in the frequency range 5 kHz to 1 MHz. The EBI spectroscopy measurements taken with dry electrodes were analyzed via the Cole and Body Composition Analysis (BCA) parameters, which were compared with EBI measurements obtained with standard electrolytic electrodes. The analysis of the obtained results indicate that even when dry textile electrodes may be used for EBI spectroscopy measurements, the measurements present remarkable differences that influence in the Cole parameter estimation process and in the final production of the BCA parameters. These initial results indicate that more research work must be done to in order to obtain a textile-based electrode that ensures reliable and reproducible EBI spectroscopy measurements.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Abtahi, Farhad, 1981-, et al.
(författare)
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Wearable Sensors Enabling Personalized Occupational Healthcare
- 2018
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Ingår i: Intelligent Environments 2018. - Amsterdam : IOS Press. - 9781614998730 - 9781614998747 ; , s. 371-376
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents needs and potentials for wearable sensors inoccupational healthcare. In addition, it presents ongoing European and Swedishprojects for developing personalized, and pervasive wearable systems for assessingrisks of developing musculoskeletal disorders and cardiovascular diseases at work.Occupational healthcare should benefit in preventing diseases and disorders byproviding the right feedback at the right time to the right person. Collected datafrom workers can provide evidence supporting the ergonomic and industrial tasksof redesigning the working environment to reduce the risks.
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| 11. |
- Atefi, Seyed Reza, 1985-, et al.
(författare)
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Cole Function and Conductance-Based Parasitic Capacitance Compensation for Cerebral Electrical Bioimpedance Measurements
- 2012
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Ingår i: Engineering in Medicine and Biology Society (EMBC), 2012 Annual International Conference of the IEEE. - San Diego : IEEE press. ; 2012, s. 3368-71
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Konferensbidrag (refereegranskat)abstract
- One of the most common measurement artifacts present in Electrical Bioimpedance Spectroscopy measurements (EBIS) comes from the capacitive leakage effect resulting from parasitic stray capacitances. This artifact produces a deviation in the measured impedance spectrum that is most noticeable at higher frequencies. The artifact taints the spectroscopy measurement increasing the difficulty of producing reliable EBIS measurements at high frequencies. In this work, an approach for removing such capacitive influence from the spectral measurement is presented making use of a novel method to estimate the value of the parasitic capacitance equivalent that causes the measurement artifact. The proposed method has been tested and validated theoretically and experimentally and it gives a more accurate estimation of the value of the parasitic capacitance than the previous methods. Once a reliable value of parasitic capacitance has been estimated the capacitive influence can be easily compensated in the EBIS measured data. Thus enabling analysis of EBIS data at higher frequencies, i.e. in the range of 300-500 kHz like measurements intended for cerebral monitoring, where the characteristic frequency is remarkably higher than EBIS measurements i.e. within the range 30 to 50 kHz, intended for body composition assessment.
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| 12. |
- Atefi, Seyed Reza, 1985-, et al.
(författare)
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Electrical Bioimpedance cerebral monitoring. Preliminary results from measurements on stroke patients
- 2012
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Ingår i: Engineering in Medicine and Biology Society (EMBC), 2012 Annual International Conference of the IEEE. - : IEEE. - 9781424441198 ; 2012, s. 126-9
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Konferensbidrag (refereegranskat)abstract
- Electrical Bioimpedance Spectroscopy (EBIS) is currently used in different tissue characterization applications. In this work we aim to use EBIS to study changes in electrical properties of the cerebral tissues after an incident of hemorrhage/ischemic stroke. To do so a case-control study was conducted using six controls and three stroke cases. The preliminary results of this study show that by using Cole-based analysis on EBIS measurements and analyzing the Cole parameters R0 and R∞, it is possible to detect changes on electrical properties of cerebral tissue after stroke.
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| 13. |
- Ayllon, David, et al.
(författare)
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Cole equation and parameter estimation from electrical bioimpedance spectroscopy measurements : A comparative study
- 2009
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Ingår i: EMBC. - Buenos Aires : IEEE Engineering in Medicine and Biology. ; , s. 3779-3782, s. 3779-3782
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Konferensbidrag (refereegranskat)abstract
- Since there are several applications of Electrical Bioimpedance (EBI) that use the Cole parameters as base of the analysis, to fit EBI measured data onto the Cole equation is a very common practice within Multifrequency-EBI and spectroscopy. The aim of this paper is to compare different fitting methods for EBI data in order to evaluate their suitability to fit the Cole equation and estimate the Cole parameters. Three of the studied fittings are based on the use of Non-Linear Least Squares on the Cole model, one using the real part only, a second using the imaginary part and the third using the complex impedance. Furthermore, a novel fitting method done on the impedance plane, without using any frequency information has been implemented and included in the comparison. Results show that the four methods perform relatively well but the best fitting in terms of standard error of estimate is the fitting obtained from the resistance only. The results support the possibility of measuring only the resistive part of the bioimpedance to accurately fit Cole equation and estimate the Cole parameters, with entailed advantages.
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| 14. |
- Benouar, Sara, et al.
(författare)
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Classification of impedance cardiography dZ/dt complex subtypes using pattern recognition artificial neural networks
- 2021
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Ingår i: Biomedizinische Technik (Berlin. Zeitschrift). - : Walter de Gruyter. - 1862-278X .- 0013-5585. ; 66:5, s. 515-527
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Tidskriftsartikel (refereegranskat)abstract
- In impedance cardiography (ICG), the detection of dZ/dt signal (ICG) characteristic points, especially the X point, is a crucial step for the calculation of hemodynamic parameters such as stroke volume (SV) and cardiac output (CO). Unfortunately, for beat-to-beat calculations, the accuracy of the detection is affected by the variability of the ICG complex subtypes. Thus, in this work, automated classification of ICG complexes is proposed to support the detection of ICG characteristic points and the extraction of hemodynamic parameters according to several existing subtypes. A novel pattern recognition artificial neural network (PRANN) approach was implemented, and a divide-and-conquer strategy was used to identify the five different waveforms of the ICG complex waveform with output nodes no greater than 3. The PRANN was trained, tested and validated using a dataset from four volunteers from a measurement of eight electrodes. Once the training was satisfactory, the deployed network was validated on two other datasets that were completely different from the training dataset. As an additional performance validation of the PRANN, each dataset included four volunteers for a total of eight volunteers. The results show an average accuracy of 96% in classifying ICG complex subtypes with only a decrease in the accuracy to 83 and 80% on the validation datasets. This work indicates that the PRANN is a promising method for automated classification of ICG subtypes, facilitating the investigation of the extraction of hemodynamic parameters from beat-to-beat dZ/dt complexes.
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| 15. |
- Benouar, Sara, et al.
(författare)
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First Steps Toward Automated Classification of Impedance Cardiography dZ/dt Complex Subtypes
- 2021
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Ingår i: 8th European Medical and Biological Engineering Conference. - Cham : Springer Science and Business Media Deutschland GmbH. - 9783030646097 - 9783030646103 ; , s. 563-573
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Konferensbidrag (refereegranskat)abstract
- The detection of the characteristic points of the complex of the impedance cardiography (ICG) is a crucial step for the calculation of hemodynamical parameters such as left ventricular ejection time, stroke volume and cardiac output. Extracting the characteristic points from the dZ/dt ICG signal is usually affected by the variability of the ICG complex and assembling average is the method of choice to smooth out such variability. To avoid the use of assembling average that might filter out information relevant for the hemodynamic assessment requires extracting the characteristics points from the different subtypes of the ICG complex. Thus, as a first step to automatize the extraction parameters, the aim of this work is to detect automatically the kind of dZ/dt complex present in the ICG signal. To do so artificial neural networks have been designed with two different configurations for pattern matching (PRANN) and tested to identify the 6 different ICG complex subtypes. One of the configurations implements a 6-classes classifier and the other implemented the divide and conquer approach classifying in two stages. The data sets used in the training, validation and testing process of the PRANNs includes a matrix of 1 s windows of the ICG complexes from the 60 s long recordings of dZ/dt signal for each of the 4 healthy male volunteers. A total of 240 s. As a result, the divide and conquer approach improve the overall classification obtained with the one stage approach on +26% reaching and average classification ration of 82%.
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| 16. |
- Benouar, Sara, et al.
(författare)
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Time-series NARX feedback neural network for forecasting impedance cardiography ICG missing points : a predictive model
- 2023
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Ingår i: Frontiers in Physiology. - : Frontiers Media S.A.. - 1664-042X. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- One of the crucial steps in assessing hemodynamic parameters using impedance cardiography (ICG) is the detection of the characteristic points in the dZ/dt ICG complex, especially the X point. The most often estimated parameters from the ICG complex are stroke volume and cardiac output, for which is required the left ventricular pre-ejection time. Unfortunately, for beat-to-beat calculations, the accuracy of detection is affected by the variability of the ICG complex subtypes. Thus, in this work, we aim to create a predictive model that can predict the missing points and decrease the previous work percentages of missing points to support the detection of ICG characteristic points and the extraction of hemodynamic parameters according to several existing subtypes. Thus, a time-series non-linear autoregressive model with exogenous inputs (NARX) feedback neural network approach was implemented to forecast the missing ICG points according to the different existing subtypes. The NARX was trained on two different datasets with an open-loop mode to ensure that the network is fed with correct feedback inputs. Once the training is satisfactory, the loop can be closed for multi-step prediction tests and simulation. The results show that we can predict the missing characteristic points in all the complexes with a success rate ranging between 75% and 88% in the evaluated datasets. Previously, without the NARX predictive model, the successful detection rate was 21%–30% for the same datasets. Thus, this work indicates a promising method and an accuracy increase in the detection of X, Y, O, and Z points for both datasets.
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| 17. |
- Brown, Shannon, et al.
(författare)
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Intarsia-sensorized band and textrodes for real-time myoelectric pattern recognition
- 2016
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Ingår i: Engineering in Medicine and Biology Society (EMBC), 2016 IEEE 38th Annual International Conference of the. - : Institute of Electrical and Electronics Engineers (IEEE). - 1557-170X. - 9781457702204 ; , s. 6074-6077
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Konferensbidrag (refereegranskat)abstract
- Surface Electromyography (sEMG) has applications in prosthetics, diagnostics and neuromuscular rehabilitation. Self-adhesive Ag/AgCl are the electrodes preferentially used to capture sEMG in short-term studies, however their long-term application is limited. In this study we designed and evaluated a fully integrated smart textile band with electrical connecting tracks knitted with intarsia techniques and knitted textile electrodes. Real-time myoelectric pattern recognition for motor volition and signal-to-noise ratio (SNR) were used to compare its sensing performance versus the conventional Ag-AgCl electrodes. After a comprehending measurement and performance comparison of the sEMG recordings, no significant differences were found between the textile and the Ag-AgCl electrodes in SNR and prediction accuracy obtained from pattern recognition classifiers.
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| 18. |
- Brown, Shannon, et al.
(författare)
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Intarsia-Sensorized Band and Textrodes for the Acquisition of Myoelectric Signals
- 2016
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Ingår i: The Second International Conference on Smart Portable, Wearable, Implantable and Disability-oriented Devices and Systems. - : International Academy, Research and Industry Association (IARIA). - 9781612084800 ; , s. 14-19
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Konferensbidrag (refereegranskat)abstract
- Surface Electromyography (sEMG) has applications in prosthetics, diagnostics and neuromuscular rehabilitation, and has been an increasing area of study. This study attempts to use a fully integrated smart textile band with electrical connecting tracks knitted with intarsia techniques to evaluate the quality of sEMG acquired by knitted textile electrodes. Myoelectric pattern recognition for motor volition and signal-to-noise ratio (SNR) were used to compare its sensing performance versus the conventional Ag-AgCl electrodes. Overall no significant differences were found between the textile and the Ag-AgCl electrodes in SNR and prediction accuracy obtained from pattern recognition classifiers. On average the textile electrodes produced a high prediction accuracy, >97% across all movements, which is equivalent to the accuracy obtained with conventional gel electrodes (Ag-AgCl). Furthermore the SNR for the Maximum Voluntary Contraction did not differ considerably between the textile and the Ag-AgCl electrodes.
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| 19. |
- Buendia, Ruben, 1983-, et al.
(författare)
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A novel approach for removing the hook effect artefact from Electrical Bioimpedance spectroscopy measurements
- 2010
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Konferensbidrag (refereegranskat)abstract
- Very often in Electrical Bioimpedance (EBI) spectroscopy measurements the presence of stray capacitances creates a measurement artefact commonly known as Hook Effect . Such an artefact creates a hook-alike deviation of the EBI data noticeable when representing the measurement on the impedance plane. Such Hook Effect is noticeable at high frequencies but it also causes a data deviation at lower measurement frequencies. In order to perform any accurate analysis of the EBI spectroscopy data, the influence of the Hook Effect must be removed. An established method to compensate the hook effect is the well known Td compensation , which consists on multiplying the obtained spectrum, Z meas (ω) by a complex exponential in the form of exp[jωTd]. Such a method cannot correct entirely the Hook Effect since the hook-alike deviation occurs a broad frequency range in both magnitude and phase of the measured impedance, and by using a scalar value for Td . First a scalar only modifies the phase of the measured impedance and second, a single value can truly corrects the Hook Effect only at a single frequency. In addition, the process to select a value for the scalar Td by an iterative process with the aim to obtain the best Cole fitting lacks solid scientific grounds. In this work the Td compensation method is revisited and a modified approach for correcting the Hook Effect including a novel method for selecting the correcting values is proposed. The initial validation results confirm that the proposed method entirely corrects the Hook Effect at all frequencies.
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| 20. |
- Buendia, Ruben, 1983-, et al.
(författare)
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Cole Parameter Estimation from the Modulus of the Electrical Bioimpeadance for Assessment of Body Composition : A Full Spectroscopy Approach
- 2011
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Ingår i: Journal of Electrical Bioimpedance. - Oslo : University of Oslo. - 1891-5469. ; 2, s. 72-78
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Tidskriftsartikel (refereegranskat)abstract
- Activities around applications of Electrical Bioimpedance Spectroscopy (EBIS) have proliferated in the past decade significantly. Most of these activities have been focused in the analysis of the EBIS measurements, which eventually might enable novel applications. In Body Composition Assessment (BCA) the most common analysis approach currently used in EBIS is based on the Cole function, which most often requires curve fitting. One of the most implemented approaches for obtaining the Cole parameters is performed in the impedance plane through the geometrical properties that the Cole function exhibit in such domain as depressed semi-circle. To fit the measured impedance data to a semi-circle in the impedance plane, obtaining the Cole parameters in an indirect and sequential manner has several drawbacks. Applying a Non-Linear Least Square (NLLS) iterative fitting on the spectroscopy measurement, obtains the Cole parameters considering the frequency information contained in the measurement. In this work, from experimental total right side EBIS measurements, the BCA parameters have been obtained to assess the amount and distribution of whole body fluids. The values for the BCA parameters have been obtained using values for the Cole parameters estimated with both approaches: circular fitting on the impedance plane and NLLS impedance-only fitting. The comparison of the values obtained for the BCA parameters with both methods confirms that the NLLS impedance-only is an effective alternative as Cole parameter estimation method in BCA from EBIS measurements. Using the modulus of the Cole function as the model for the fitting would eliminate the need for performing a phase detection in the acquisition process, simplifying the hardware specifications of the measurement instrumentation when implementing a bioimpedance spectrometer.
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| 21. |
- Buendia, Ruben, 1983-, et al.
(författare)
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Cole parameter estimation from total right side electrical bioimpedance spectroscopy measurements : Influence of the number of frequencies and the upper limit
- 2011
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Ingår i: 2011 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC). - : IEEE. - 9781424441211 - 9781424441228 ; , s. 1843-1846
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Konferensbidrag (refereegranskat)abstract
- Applications based on measurements of Electrical Bioimpedance Spectroscopy (EBIS) analysis are proliferating. The most spread and known application of EBIS is the non-invasive assessment of body composition. Fitting to the Cole function to obtain the Cole parameters, R0 and R∞, is the core of the EBIS analysis to obtain the body fluid distribution. An accurate estimation of the Cole parameters is essential for the Body Composition Assessment (BCA) and the estimation process depends on several factors. One of them is the upper frequency limit used for the estimation and the other is the number of measured frequencies in the measurement frequency range. Both of them impose requirements on the measurement hardware, influencing largely in the complexity of the bioimpedance spectrometer. In this work an analysis of the error obtained when estimating the Cole parameters with several frequency ranges and different number of frequencies has been performed. The study has been done on synthetic EBIS data obtained from experimental Total Right Side (TRS) measurements. The results suggest that accurate estimations of R0 and R∞ for BCA measurements can be achieved using much narrower frequency ranges and quite fewer frequencies than electrical bioimpedance spectrometers commercially available nowadays do.
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| 22. |
- Buendia, Ruben, 1982, et al.
(författare)
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Estimation of body fluids with bioimpedance spectroscopy: state of the art methods and proposal of novel methods
- 2015
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Ingår i: Physiological Measurement. - : IOP Publishing. - 0967-3334 .- 1361-6579. ; 36:10
-
Tidskriftsartikel (refereegranskat)abstract
- Determination of body fluids is a useful common practice in determination of disease mechanisms and treatments. Bioimpedance spectroscopy (BIS) methods are non-invasive, inexpensive and rapid alternatives to reference methods such as tracer dilution. However, they are indirect and their robustness and validity are unclear. In this article, state of the art methods are reviewed, their drawbacks identified and new methods are proposed. All methods were tested on a clinical database of patients receiving growth hormone replacement therapy. Results indicated that most BIS methods are similarly accurate (e.g. < 0.5 +/- 3.0% mean percentage difference for total body water) for estimation of body fluids. A new model for calculation is proposed that performs equally well for all fluid compartments (total body water, extra-and intracellular water). It is suggested that the main source of error in extracellular water estimation is due to anisotropy, in total body water estimation to the uncertainty associated with intracellular resistivity and in determination of intracellular water a combination of both.
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| 23. |
- Buendia, Ruben, 1982, et al.
(författare)
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Experimental Validation of a Method for Removing the Capacitive Leakage Artifact from Electrical Bioimpedance Spectroscopy Measurements
- 2010
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Ingår i: Measurement Science and Technology. - : IOP Publishing. - 0957-0233 .- 1361-6501. ; 21:11, s. 115802-
-
Tidskriftsartikel (refereegranskat)abstract
- Often when performing electrical bioimpedance (EBI) spectroscopy measurements, the obtained EBI data present a hook-like deviation, which is most noticeable at high frequencies in the impedance plane. The deviation is due to a capacitive leakage effect caused by the presence of stray capacitances. In addition to the data deviation being remarkably noticeable at high frequencies in the phase and the reactance spectra, the measured EBI is also altered in the resistance and the modulus. If this EBI data deviation is not properly removed, it interferes with subsequent data analysis processes, especially with Cole model-based analyses. In other words, to perform any accurate analysis of the EBI spectroscopy data, the hook deviation mustbe properly removed. Td compensation is a method used to compensate the hook deviation present in EBI data; it consists of multiplying the obtained spectrum, Zmeas(ω), by a complex exponential in the form of exp(–jωTd). Although the method is well known and accepted, Td compensation cannot entirely correct the hook-like deviation; moreover, it lacks solid scientific grounds. In this work, the Td compensation method is revisited, and it is shown that it should not be used to correct the effect of a capacitive leakage; furthermore, a more developed approach for correcting the hook deviation caused by the capacitive leakage is proposed. The method includes a novel correcting expression and a process for selecting the proper values of expressions that are complex and frequency dependent. The correctness of the novel method is validated with the experimental data obtained from measurements from three different EBI applications. The obtained results confirm the sufficiency and feasibility of the correcting method.
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| 24. |
- Buendia, Ruben, 1983-, et al.
(författare)
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Hook Effect correction & resistance-based Cole fitting prior Cole model-based analysis : Experimental validation
- 2010
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Ingår i: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2010. - : IEEE Engineering in Medicine and Biology. ; , s. 6563-6566
-
Konferensbidrag (refereegranskat)abstract
- The analysis of measurements of Electrical Bioimpedance (EBI) is on the increase for performing non-invasive assessment of health status and monitoring of pathophysiological mechanisms. EBI measurements might contain measurements artefacts that must be carefully removed prior to any further analysis. Cole model-based analysis is often selected when analysing EBI data and might lead to miss-conclusion if it is applied on data contaminated with measurement artefacts. The recently proposed Correction Function to eliminate the influence of the Hook Effect from EBI data and the fitting to the real part of the Cole model to extract the Cole parameters have been validated on experimental measurements. The obtained results confirm the feasible experimental use of these promising pre-processing tools that might improve the outcome of EBI applications using Cole model-based analysis.
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| 25. |
- Buendia, Ruben, 1983-, et al.
(författare)
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Influence of electrode mismatch on Cole parameter estimation from Total Right Side Electrical Bioimpedance Spectroscopy measurements
- 2012
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Ingår i: Medical Engineering and Physics. - : Elsevier BV. - 1350-4533 .- 1873-4030. ; 34:7, s. 1024-1028
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Tidskriftsartikel (refereegranskat)abstract
- Applications based on measurements of Electrical Bioimpedance (EBI) spectroscopy analysis, like assessment of body composition, have proliferated in the past years. Currently Body Composition Assessment (BCA) based in Bioimpedance Spectroscopy (BIS) analysis relays on an accurate estimation of the Cole parameters R-0 and R-infinity. A recent study by Bogonez-Franco et al. has proposed electrode mismatch as source of remarkable artefacts in BIS measurements. Using Total Right Side BIS measurements from the aforementioned study, this work has focused on the influence of electrode mismatch on the estimation of R-0 and R-infinity using the Non-Linear Least Square curve fitting technique on the modulus of the impedance. The results show that electrode mismatch on the voltage sensing electrodes produces an overestimation of the impedance spectrum leading to a wrong estimation of the parameters R-0 and R-infinity, and consequently obtaining values around 4% larger that the values obtained from BIS without electrode mismatch. The specific key factors behind electrode mismatch or its influence on the analysis of single and spectroscopy measurements have not been investigated yet, no compensation or correction technique is available to overcome the deviation produced on the EBI measurement. Since textile-enabled EBI applications using dry textrodes, i.e. textile electrodes with dry skin-electrode interfaces and potentially large values of electrode polarization impedance are more prone to produce electrode mismatch, the lack of a correction or compensation technique might hinder the proliferation of textile-enabled EBI applications for personalized healthcare monitoring.
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| 26. |
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| 27. |
- Buendia, Rubén, et al.
(författare)
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Robustness study of the different immittance spectra and frequency ranges in bioimpedance spectroscopy analysis for assessment of total body composition.
- 2014
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Ingår i: Physiological measurement. - : IOP Publishing. - 1361-6579 .- 0967-3334. ; 35:7, s. 1373-95
-
Tidskriftsartikel (refereegranskat)abstract
- The estimation of body fluids is a useful and common practice for assessment of disease status and therapy outcomes. Electrical bioimpedance spectroscopy (EBIS) methods are noninvasive, inexpensive and efficient alternatives for determination of body fluids. One of the main source of errors in EBIS measurements in the estimation of body fluids is capacitive coupling. In this paper an analysis of capacitive coupling in EBIS measurements was performed and the robustness of the different immittance spectra against it tested. On simulations the conductance (G) spectrum presented the smallest overall error, among all immittance spectra, in the estimation of the impedance parameters used to estimate body fluids. Afterwards the frequency range of 10-500kHz showed to be the most robust band of the G spectrum. The accuracy of body fluid estimations from the resulting parameters that utilized G spectrum and parameters provided by the measuring device were tested on EBIS clinical measurements from growth hormone replacement therapy patients against estimations performed with dilution methods. Regarding extracellular fluid, the correlation between each EBIS method and dilution was 0.93 with limits of agreement of 1.06 ± 2.95 l for the device, 1.10 ± 2.94 l for G [10-500kHz] and 1.04 ± 2.94 l for G [5-1000kHz]. Regarding intracellular fluid, the correlation between dilution and the device was 0.91, same as for G [10-500kHz] and 0.92 for G [5-1000kHz]. Limits of agreement were 0.12 ± 4.46 l for the device, 0.09 ± 4.45 for G [10-500kHz] and 0.04 ± 4.58 for G [5-1000kHz]. Such close results between the EBIS methods validate the proposed approach of using G spectrum for initial Cole characterization and posterior clinical estimation of body fluids status.
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| 28. |
- Chen, Kaile, et al.
(författare)
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Process mining and data mining applications in the domain of chronic diseases : A systematic review
- 2023
-
Ingår i: Artificial Intelligence in Medicine. - : Elsevier BV. - 0933-3657 .- 1873-2860. ; 144
-
Forskningsöversikt (refereegranskat)abstract
- The widespread use of information technology in healthcare leads to extensive data collection, which can be utilised to enhance patient care and manage chronic illnesses. Our objective is to summarise previous studies that have used data mining or process mining methods in the context of chronic diseases in order to identify research trends and future opportunities. The review covers articles that pertain to the application of data mining or process mining methods on chronic diseases that were published between 2000 and 2022. Articles were sourced from PubMed, Web of Science, EMBASE, and Google Scholar based on predetermined inclusion and exclusion criteria. A total of 71 articles met the inclusion criteria and were included in the review. Based on the literature review results, we detected a growing trend in the application of data mining methods in diabetes research. Additionally, a distinct increase in the use of process mining methods to model clinical pathways in cancer research was observed. Frequently, this takes the form of a collaborative integration of process mining, data mining, and traditional statistical methods. In light of this collaborative approach, the meticulous selection of statistical methods based on their underlying assumptions is essential when integrating these traditional methods with process mining and data mining methods. Another notable challenge is the lack of standardised guidelines for reporting process mining studies in the medical field. Furthermore, there is a pressing need to enhance the clinical interpretation of data mining and process mining results.
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| 29. |
- Cheng, Jingyuan, et al.
(författare)
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Textile Building Blocks:Toward Simple, Modularized, and Standardized Smart Textile
- 2017
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Ingår i: Smart Textiles. - Cham : Springer, Cham. - 9783319501239 - 9783319501246 ; , s. 303-331
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Bokkapitel (refereegranskat)abstract
- Textiles are pervasive in our life, covering human body and objects, as well as serving in industrial applications. In its everyday use of individuals, smart textile becomes a promising medium for monitoring, information retrieval, and interaction. While there are many applications in sport, health care, and industry, the state-of-the-art smart textile is still found only in niche markets. To gain mass-market capabilities, we see the necessity of generalizing and modularizing smart textile production and application development, which on the one end lowers the production cost and on the other end enables easy deployment. In this chapter, we demonstrate our initial effort in modularization. By devising types of universal sensing fabrics for conductive and non-conductive patches, smart textile construction from basic, reusable components can be made. Using the fabric blocks, we present four types of sensing modalities, including resistive pressure, capacitive, bioimpedance, and biopotential. In addition, we present a multi-channel textile–electronics interface and various applications built on the top of the basic building blocks by ‘cut and sew’ principle.
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| 30. |
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| 31. |
- Fernandez-Llatas, Carlos, et al.
(författare)
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Empowering ergonomy in workplaces by individual behavior modeling using interactive process mining paradigm
- 2018
-
Ingår i: Intelligent Environments 2018. - Amsterdam : IOS Press. - 9781614998730 - 9781614998747 ; , s. 346-354
-
Bokkapitel (refereegranskat)abstract
- Work-related disorders account for a significant part of total healthcareexpenditure. Traditionally muscle-skeletal disorders were predominant as source ofwork absenteeism but in last years work activity-related disorders have increasedremarkably. Too little activity at work, sedentarism, or too much work activity leadsto stress. The individualized behavioural analysis of patients could support ergon-omy experts in the optimization of workplaces in a Healthier way. Process MiningTechnologies can offer a human understandable view of what is actually occurringin workplaces in an individualized way. In this paper, we present a proof of con-cept of how Process Mining technologies can be used for discovering the workerflow in order to support the ergonomy experts in the selection of more accurateinterventions for improving occupational health.
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| 32. |
- Ferreira, Javier, 1982-, et al.
(författare)
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A handheld and textile-enabled bioimpedance system for ubiquitous body composition analysis. : An initial functional validation
- 2016
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Ingår i: IEEE journal of biomedical and health informatics. - : Institute of Electrical and Electronics Engineers (IEEE). - 2168-2194 .- 2168-2208. ; 21:5
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, many efforts have been made to promote a healthcare paradigm shift from the traditional reactive hospital-centered healthcare approach towards a proactive, patient-oriented and self-managed approach that could improve service quality and help reduce costs while contributing to sustainability. Managing and caring for patients with chronic diseases accounts over 75% of healthcare costs in developed countries. One of the most resource demanding diseases is chronic kidney disease (CKD), which often leads to a gradual and irreparable loss of renal function, with up to 12% of the population showing signs of different stages of this disease. Peritoneal dialysis and home haemodialysis are life-saving home-based renal replacement treatments that, compared to conventional in-center hemodialysis, provide similar long-term patient survival, less restrictions of life-style, such as a more flexible diet, and better flexibility in terms of treatment options and locations. Bioimpedance has been largely used clinically for decades in nutrition for assessing body fluid distributions. Moreover, bioimpedance methods are used to assess the overhydratation state of CKD patients, allowing clinicians to estimate the amount of fluid that should be removed by ultrafiltration. In this work, the initial validation of a handheld bioimpedance system for the assessment of body fluid status that could be used to assist the patient in home-based CKD treatments is presented. The body fluid monitoring system comprises a custom-made handheld tetrapolar bioimpedance spectrometer and a textile-based electrode garment for total body fluid assessment. The system performance was evaluated against the same measurements acquired using a commercial bioimpedance spectrometer for medical use on several voluntary subjects. The analysis of the measurement results and the comparison of the fluid estimations indicated that both devices are equivalent from a measurement performance perspective, allowing for its use on ubiquitous e-healthcare dialysis solutions.
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| 33. |
- Ferreira, Javier, 1982-, et al.
(författare)
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AD5933-based Spectrometer for Electrical Bioimpedance Applications
- 2010
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596. ; 224:1, s. 012011-
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Konferensbidrag (refereegranskat)abstract
- o build an Electrical Bioimpedance (EBI) spectrometer using the Impedance Measurement System-On-Chip AD5933 together with a 4-Electrode Analog Front End (4E-AFE) has been proven practicable. Such small measurement devices can make possible several new applications of EBI technology, especially when combined with functional textiles, which can enable wearable applications for personal health and home monitoring. After the implementation and functional validation of the 4E-AFE-enabled spectrometer, the next natural step is to validate for which EBI applications the 4E-AFE-enabled system is suitable. To test the applicability of this novel spectrometer on several EBI applications, 2R1C equivalent models have been experimentally obtained and impedance spectroscopy measurements have been performed with the system under study and with the SFB7 EBI spectrometer manufactured by ImpediMed. The 2R1C circuit parameters have been estimated with the BioImp software from the spectra obtained with both EBI spectrometers and the estimated values have been compared with the original values used in each circuit model implementation. The obtained results indicated that the 4E-AFE-enabled system cannot beat the performance of the SFB7 in accuracy but it performs better in preciseness. In any case the overall performance indicates that the 4E-AFE-enabled system can perform spectroscopy measurements in the frequency range from 5 to 100 kHz.
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| 34. |
- Garrote, Ramon, et al.
(författare)
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Design-Build Experience-Based Program in Biomedical Engineering as a Practical Example of Science for Professions
- 2010
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Ingår i: Proceedings of EDULEARN10 Conference. - Barcelona : International Association for Technology, Education and Development. ; , s. 110-113
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Konferensbidrag (refereegranskat)abstract
- In this paper the authors present a solution to the problem of giving practical training in handling information and communication technology (ICT) without depending on internet access. The proposed method is to use an USB-memory to emulate selected educational resources that are otherwise available on the internet or on a local network. How this method can influence pedagogical issues is discussed and, it is asserted that the method offers interesting learning advantages beyond the obvious independence of internet connections. The paper describes the planning and implementation of a course about the use of Learning Management Systems (LMS) in higher education and, in particular, how it was designed to meet the needs of educators in a developing country with slow or unreliable internet connections. The course was a part of the project USo+I: Universidad, Sociedad e Innovación. Mejora de la pertinencia de la educación en las ingenierías de Latinoamérica (University and Society: Improving of the relevance of the education in the engineering of Latinoamerica) this project financed by the European Union, within the ALFA III program. The University of Borås was assigned to design and teach a course about LMS to engineering educators in Latin-America.
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| 35. |
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| 36. |
- Gunnarsson, Emanuel
(författare)
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On the elements of E-textiles : Fabrication and characterisation of textile routing and electrodes
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- “Smart textile” as a notion was demarcated approximately 25 years ago, leading to an enthusiastic hype around the research. Both academic efforts and members of the maker community developed prototypes and artistic creations that incorporated smart features into textiles. From the start of this research era, numerous authors suggested that smart textiles had the potential to revolutionise the healthcare sector. At around the same time, the European Commission had started raising concerns about the demographic trends in Europe, with an ageing population and decreasing birth rates. The need for long-term solutions to address the predicted increase in healthcare demands became evident. Despite 25 years of research with many papers suggesting a soon-to-come commercial breakthrough for smart textiles, such a breakthrough has yet to be seen. There is only a handful of smart textile products on the market currently, and the much-anticipated improvement in the healthcare sector promised by smart textile research is still absent. At the time of writing this thesis, the European Standardisation Committee (CEN) expresses the view that part of the reason for the lack of a commercial breakthrough for smart textiles is the absence of regulations and standards. Technical reports and testing standards regarding smart textiles are being issued continuously by both the International Electrotechnical Committee (IEC), the CEN and the International Organization for Standardization (ISO). These organisations also strive to harmonise the issued guidelines. It is crucial that these regulatory documents describe metrics that are relevant to the applications. Moreover, if easily adopted textile-friendly methods for producing smart textile elements were available to potential producers, in addition to these regulations, the preconditions for a less financially risky market with better functioning smart textile products could be established. This, in turn, might stimulate an increase in the production of smart textile products intended for personalised health. This thesis summarises several aspects of smart textile intended for personalised health (P-health). It provides both suggestions on how to test elements of the textiles properly (their interface with the human body) and how to manufacture components of a smart textile system, such as electrodes and electrical routing. The main objectives of the work behind this thesis include: 1) investigating how functional building blocks for smart textile garments intended for p-health can be manufactured in a textile-friendly way and 2) investigating how to characterise these building blocks in the most appropriate way. It is concluded that such building blocks can be produced and used for smart textile garments in both daily life activities and therapeutic situations. The thesis demonstrates the production of electrically insulated routing integrated into a textile fabric, all done in a single textile production step. For the measurement methods, it is argued that skin-electrode impedance between human subjects and textile electrodes should be measured in-vivo using a three-electrode setup. Additionally, the thesis proposes that instead of measuring sheet resistance, it is better to measure the resistance of the specific smart textile element, as it is shown that sheet resistance is not always applicable to conductive fabrics made from interlaced conductive yarns.
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| 37. |
- Gunnarsson, Emanuel, et al.
(författare)
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Seamlessly integrated textile electrodes and conductive routing in a garment for electrostimulation: design, manufacturing and evaluation
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Electro-stimulation to alleviate spasticity, pain and to increase mobility has been used successfully for years. Usually, gelled electrodes are used for this. In a garment intended for repeated use such electrodes must be replaced. The Mollii-suit by the company Inerventions utilises dry conductive rubber electrodes. The electrodes work satisfactory, but the garment is cumbersome to fit on the body. In this paper we show that knitted dry electrodes can be used instead. The knitted electrodes present a lower friction against the skin and a garment is easily fitted to the body. The fabric is stretchable and provides a tight fit to the body ensuring electrical contact. We present three candidate textrodes and show how we choose the one with most favourable features for producing the garment. We validate the performance of the garment by measuring three electrical parameters: rise time (10–90%) of the applied voltage, net injected charge and the low frequency value of the skin–electrode impedance. It is concluded that the use of flat knitting intarsia technique can produce a garment with seamlessly integrated conductive leads and electrodes and that this garment delivers energy to the body as targeted and is beneficial from manufacturing and comfort perspectives.
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| 38. |
- Gunnarsson, Emanuel, et al.
(författare)
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Three-lead in vivo measurement method for determining the skin-electrode impedance of textile electrodes : A fast, accurate and easy-to-use measurement method suitable for characterization of textile electrodes
- 2023
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Ingår i: Textile research journal. - : SAGE Open. - 0040-5175 .- 1746-7748.
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Tidskriftsartikel (refereegranskat)abstract
- The rise of interest in wearable sensing of bioelectrical signals conducted via smart textile systems over the past decades has resulted in many investigations on how to develop and evaluate such systems. All measurements of bioelectrical signals are done by way of electrodes. The most critical parameter for an electrode is the skin-electrode impedance. A common method for measuring skin-electrode impedance is the two-lead method, but it has limitations because it relies on assumptions of symmetries of the body impedance in different parts of the body as well as of the skin-electrode impedances. To address this, in this paper we present an easy-to-use and reliable three-lead in vivo method as a more accurate alternative. We aim to show that the in vivo three-lead method overcomes all such limitations. We aim at raising the awareness regarding the possibility to characterize textile electrodes using a correct, accurate and robust method rather than limited and sometimes inadequate and uninformative methods. The three-lead in vivo method eliminates the effect of body impedance as well as all other contact impedances during measurements. The method is direct and measures only the skin-electrode impedance. This method is suitable for characterization of skin-electrode interface of textile electrodes intended for both bioelectrical signals as well as for electrostimulation of the human body. We foresee that the utilization of the three-lead in vivo method has the potential to impact the further development of wearable sensing by enabling more accurate and reliable measurement of bioelectrical signals.
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| 39. |
- Hafid, Abdelakram, et al.
(författare)
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Evaluation of dZ/dt Complex Subtypes vs Ensemble Averaging Method for Estimation of Left Ventricular Ejection Time from ICG Recording
- 2021
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Ingår i: 8th European Medical and Biological Engineering ConferenceProceedings of the EMBEC 2020, November 29 – December 3, 2020 Portorož, Slovenia. - Cham : Springer Science and Business Media Deutschland GmbH. - 9783030646097 - 9783030646103 ; , s. 502-509
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Konferensbidrag (refereegranskat)abstract
- Impedance cardiography (ICG) was discovered nearly half a century ago, being proposed as noninvasive monitoring method for estimation of several hemodynamics parameter. Despite of nearly 5 decades of clinical research and use there is still certain controversy about its performance when estimating Left Ventricular Ejection Time (LVET). This work present a comparison between using the different ICG subtype waveform and the ensemble averaged (EA) method to calculate the LVET. The ICG has been recorded from four volunteers, and the LVET parameter has been calculated using the two approaches. The result shows that each volunteer have different percentage of subtypes, and the mean relative error between the two approaches for estimation of LVET varied between 0.62 to 2.9% with an average mean absolute percentage error of 18,02% ranging between 13.82 to 18.42%. © 2021, Springer Nature Switzerland AG.
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| 40. |
- Hafid, Abdelakram, et al.
(författare)
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Full Impedance Cardiography Measurement Device Using Raspberry PI3 and System-on-Chip Biomedical Instrumentation Solutions
- 2018
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Ingår i: IEEE journal of biomedical and health informatics. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2168-2194 .- 2168-2208. ; 22:6, s. 1883-1894
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 41. |
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| 42. |
- Hafid, Abdelakram, et al.
(författare)
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Sensorized T-Shirt with Intarsia-Knitted Conductive Textile Integrated Interconnections: Performance Assessment of Cardiac Measurements during Daily Living Activities
- 2023
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Ingår i: Sensors. - 1424-8220. ; 23:22
-
Tidskriftsartikel (refereegranskat)abstract
- The development of smart wearable solutions for monitoring daily life health status is increasingly popular, with chest straps and wristbands being predominant. This study introduces a novel sensorized T-shirt design with textile electrodes connected via a knitting technique to a Movesense device. We aimed to investigate the impact of stationary and movement actions on electrocardiography (ECG) and heart rate (HR) measurements using our sensorized T-shirt. Various activities of daily living (ADLs), including sitting, standing, walking, and mopping, were evaluated by comparing our T-shirt with a commercial chest strap. Our findings demonstrate measurement equivalence across ADLs, regardless of the sensing approach. By comparing ECG and HR measurements, we gained valuable insights into the influence of physical activity on sensorized T-shirt development for monitoring. Notably, the ECG signals exhibited remarkable similarity between our sensorized T-shirt and the chest strap, with closely aligned HR distributions during both stationary and movement actions. The average mean absolute percentage error was below 3%, affirming the agreement between the two solutions. These findings underscore the robustness and accuracy of our sensorized T-shirt in monitoring ECG and HR during diverse ADLs, emphasizing the significance of considering physical activity in cardiovascular monitoring research and the development of personal health applications.
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| 43. |
- Illueca Fernández, Eduardo, et al.
(författare)
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Sequence-oriented sensitive analysis for PM2.5 exposure and risk assessment using interactive process mining
- 2023
-
Ingår i: PLOS ONE. - 1932-6203. ; 18:8, s. e0290372-e0290372
-
Tidskriftsartikel (refereegranskat)abstract
- The World Health Organization has estimated that air pollution will be one of the most significant challenges related to the environment in the following years, and air quality monitoring and climate change mitigation actions have been promoted due to the Paris Agreement because of their impact on mortality risk. Thus, generating a methodology that supports experts in making decisions based on exposure data, identifying exposure-related activities, and proposing mitigation scenarios is essential. In this context, the emergence of Interactive Process Mining—a discipline that has progressed in the last years in healthcare—could help to develop a methodology based on human knowledge. For this reason, we propose a new methodology for a sequence-oriented sensitive analysis to identify the best activities and parameters to offer a mitigation policy. This methodology is innovative in the following points: i) we present in this paper the first application of Interactive Process Mining pollution personal exposure mitigation; ii) our solution reduces the computation cost and time of the traditional sensitive analysis; iii) the methodology is human-oriented in the sense that the process should be done with the environmental expert; and iv) our solution has been tested with synthetic data to explore the viability before the move to physical exposure measurements, taking the city of Valencia as the use case, and overcoming the difficulty of performing exposure measurements. This dataset has been generated with a model that considers the city of Valencia’s demographic and epidemiological statistics. We have demonstrated that the assessments done using sequence-oriented sensitive analysis can identify target activities. The proposed scenarios can improve the initial KPIs—in the best scenario; we reduce the population exposure by 18% and the relative risk by 12%. Consequently, our proposal could be used with real data in future steps, becoming an innovative point for air pollution mitigation and environmental improvement.
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| 44. |
- Jacobsson, Martin, 1976-, et al.
(författare)
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The role of compression in large scale data transfer and storage of typical biomedical signals at hospitals
- 2023
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Ingår i: Health Informatics Journal. - : Sage Publications. - 1460-4582 .- 1741-2811. ; 29:4
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Tidskriftsartikel (refereegranskat)abstract
- In modern hospitals, monitoring patients’ vital signs and other biomedical signals is standard practice. With the advent of data-driven healthcare, Internet of medical things, wearable technologies, and machine learning, we expect this to accelerate and to be used in new and promising ways, including early warning systems and precision diagnostics. Hence, we see an ever-increasing need for retrieving, storing, and managing the large amount of biomedical signal data generated. The popularity of standards, such as HL7 FHIR for interoperability and data transfer, have also resulted in their use as a data storage model, which is inefficient. This article raises concern about the inefficiency of using FHIR for storage of biomedical signals and instead highlights the possibility of a sustainable storage based on data compression. Most reported efforts have focused on ECG signals; however, many other typical biomedical signals are understudied. In this article, we are considering arterial blood pressure, photoplethysmography, and respiration. We focus on simple lossless compression with low implementation complexity, low compression delay, and good compression ratios suitable for wide adoption. Our results show that it is easy to obtain a compression ratio of 2.7:1 for arterial blood pressure, 2.9:1 for photoplethysmography, and 4.1:1 for respiration.
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| 45. |
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| 46. |
- Löfhed, Johan, et al.
(författare)
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Soft textile electrodes for EEG monitoring
- 2010
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Konferensbidrag (refereegranskat)abstract
- There is a need for long term monitoring of the brain during intensive care. This is e.g. the case for newborn babies that have been exposed to hypoxia during delivery. Electroencephalography (EEG) is the technique of choice. To get a clear and detailed view of the brain activity a large number of EEG electrodes should be used. Applying traditional electrodes one by one is a time-consuming and technically demanding work and therefore electrode caps are sometimes used. The existing caps have however been found to be suboptimal for long term monitoring because they may induce too high a pressure on the scalp of the babies. We have tested three different types of textile electrodes with regard to their potential use for EEG monitoring. The results show that soft conducting textile materials can indeed be used for EEG monitoring.
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| 47. |
- Löfhede, Johan, 1978, et al.
(författare)
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Soft Textile Electrodes for EEG Monitoring
- 2010
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Ingår i: [12]10th IEEE International Conference on Information Technology and Applications.
-
Konferensbidrag (refereegranskat)
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| 48. |
- Löfhede, Johan, 1980-, et al.
(författare)
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Textile Electrodes for EEG Recording : A Pilot Study
- 2012
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Ingår i: Sensors. - Basel : MDPI. - 1424-8220. ; 12:12, s. 16907-16919
-
Tidskriftsartikel (refereegranskat)abstract
- The overall aim of our research is to develop a monitoring system for neonatal intensive care units. Long-term EEG monitoring in newborns require that the electrodes don’t harm the sensitive skin of the baby, an especially relevant feature for premature babies. Our approach to EEG monitoring is based on several electrodes distributed over the head of the baby, and since the weight of the head always will be on some of them, any type of hard electrode will inevitably cause a pressure-point that can irritate the skin. Therefore, we propose the use of soft conductive textiles as EEG electrodes, primarily for neonates, but also for other kinds of unobtrusive long-term monitoring. In this paper we have tested two types of textile electrodes on five healthy adults and compared them to standard high quality electrodes. The acquired signals were compared with respect to morphology, frequency distribution, spectral coherence, correlation and power line interference sensitivity, and the signals were found to be similar in most respects. The good measurement performance exhibited by the textile electrodes indicates that they are feasible candidates for EEG recording, opening the door for long-term EEG monitoring applications.
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| 49. |
- Malm, Veronica, et al.
(författare)
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Characterisation of Electrical and Stiffness Properties of Conductive Textile Coatings with Metal Flake-shaped Fillers
- 2019
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 12:21, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Two conductive formulations containing different types of micron-sized metal flakes (silver-coated copper (Cu) and pure silver (Ag)) were characterised and used to form highly electrically conductive coatings (conductors) on plain and base-coated woven fabrics, the latter in an encapsulated construction. With e-textiles as the intended application, the fabric stiffness, in terms of flexural stiffness and sheet resistance (Rsh), after durability testing (laundering and abrasion) was investigated and related to user friendliness and long-term performance. Bare and encapsulated conductors with increasing amounts of deposited solids were fabricated by adjusting the knife coating parameters, such as the coating gap height (5, 20, 50, and 200 μm), which reduced the Rsh, as determined by four-point probe (4PP) measurements; however, this improvement was at the expense of increased flexural stiffness of the coated fabrics. The addition of a melamine derivative (MF) as a cross-linker to the Cu formulation and the encapsulation of both conductor types gave the best trade-off between durability and Rsh, as confirmed by 4PP measurements. However, the infrared camera images revealed the formation of hotspots within the bare conductor matrix, although low resistances (determined by 4PP) and no microstructural defects (determined by SEM) were detected. These results stress the importance of thorough investigation to assure the design of reliable conductors applied on textiles requiring this type of maintenance.
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| 50. |
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