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Mohino-Herranz I, Gil-Pita R, García-Gómez J, Rosa-Zurera M, Seoane F. A Wrapper Feature Selection Algorithm: An Emotional Assessment Using Physiological Recordings from Wearable Sensors. Sensors (Basel) 2020; 20:s20010309. [PMID: 31935893 PMCID: PMC6983098 DOI: 10.3390/s20010309] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/29/2019] [Accepted: 01/03/2020] [Indexed: 11/16/2022]
Abstract
Assessing emotional state is an emerging application field boosting research activities on the topic of analysis of non-invasive biosignals to find effective markers to accurately determine the emotional state in real-time. Nowadays using wearable sensors, electrocardiogram and thoracic impedance measurements can be recorded, facilitating analyzing cardiac and respiratory functions directly and autonomic nervous system function indirectly. Such analysis allows distinguishing between different emotional states: neutral, sadness, and disgust. This work was specifically focused on the proposal of a k-fold approach for selecting features while training the classifier that reduces the loss of generalization. The performance of the proposed algorithm used as the selection criterion was compared to the commonly used standard error function. The proposed k-fold approach outperforms the conventional method with 4% hit success rate improvement, reaching an accuracy near to 78%. Moreover, the proposed selection criterion method allows the classifier to produce the best performance using a lower number of features at lower computational cost. A reduced number of features reduces the risk of overfitting while a lower computational cost contributes to implementing real-time systems using wearable electronics.
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Affiliation(s)
- Inma Mohino-Herranz
- Department of Signal Theory and Communications, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain; (R.G.-P.); (J.G.-G.); (M.R.-Z.)
- Correspondence:
| | - Roberto Gil-Pita
- Department of Signal Theory and Communications, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain; (R.G.-P.); (J.G.-G.); (M.R.-Z.)
| | - Joaquín García-Gómez
- Department of Signal Theory and Communications, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain; (R.G.-P.); (J.G.-G.); (M.R.-Z.)
| | - Manuel Rosa-Zurera
- Department of Signal Theory and Communications, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain; (R.G.-P.); (J.G.-G.); (M.R.-Z.)
| | - Fernando Seoane
- Institute for Clinical Science, Intervention and Technology, Karolinska Institutet, 17177 Solna Stockholm, Sweden;
- Department of Medical Care Technology, Karolinska University Hospital, 14157 Huddinge, Sweden
- Textile Materials Technology, Department of Textile Technology, Faculty of Textiles, Engineering and Businees Swedish School of Textiles, University of Boras, 50190 Boras, Sweden
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Mohino-Herranz I, Gil-Pita R, Rosa-Zurera M, Seoane F. Activity Recognition Using Wearable Physiological Measurements: Selection of Features from a Comprehensive Literature Study. Sensors (Basel) 2019; 19:E5524. [PMID: 31847261 PMCID: PMC6960825 DOI: 10.3390/s19245524] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/07/2019] [Accepted: 12/11/2019] [Indexed: 11/17/2022]
Abstract
Activity and emotion recognition based on physiological signal processing in health care applications is a relevant research field, with promising future and relevant applications, such as health at work or preventive care. This paper carries out a deep analysis of features proposed to extract information from the electrocardiogram, thoracic electrical bioimpedance, and electrodermal activity signals. The activities analyzed are: neutral, emotional, mental and physical. A total number of 533 features are tested for activity recognition, performing a comprehensive study taking into consideration the prediction accuracy, feature calculation, window length, and type of classifier. Feature selection to know the most relevant features from the complete set is implemented using a genetic algorithm, with a different number of features. This study has allowed us to determine the best number of features to obtain a good error probability avoiding over-fitting, and the best subset of features among those proposed in the literature. The lowest error probability that is obtained is 22.2%, with 40 features, a least squares error classifier, and 40 seconds window length.
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Affiliation(s)
- Inma Mohino-Herranz
- Department of Signal Theory and Communications, University of Alcala, 28805 Alcala de Henares, Madrid, Spain; (R.G.-P.); (M.R.-Z.)
| | - Roberto Gil-Pita
- Department of Signal Theory and Communications, University of Alcala, 28805 Alcala de Henares, Madrid, Spain; (R.G.-P.); (M.R.-Z.)
| | - Manuel Rosa-Zurera
- Department of Signal Theory and Communications, University of Alcala, 28805 Alcala de Henares, Madrid, Spain; (R.G.-P.); (M.R.-Z.)
| | - Fernando Seoane
- Clinical Science, Intervention an Technology, Karolinska Institutet, 17177 Stockholm, Sweden;
- Department Biomedical Engineering, Karolinska University Hospital, 14186 Stockholm, Sweden
- Swedish School of Textiles, University of Boras, 50190 Boras, Sweden
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García-Gómez J, Gil-Pita R, Rosa-Zurera M, Romero-Camacho A, Jiménez-Garrido JA, García-Benavides V. Smart Sound Processing for Defect Sizing in Pipelines Using EMAT Actuator Based Multi-Frequency Lamb Waves. Sensors (Basel) 2018. [PMID: 29518927 PMCID: PMC5876749 DOI: 10.3390/s18030802] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pipeline inspection is a topic of particular interest to the companies. Especially important is the defect sizing, which allows them to avoid subsequent costly repairs in their equipment. A solution for this issue is using ultrasonic waves sensed through Electro-Magnetic Acoustic Transducer (EMAT) actuators. The main advantage of this technology is the absence of the need to have direct contact with the surface of the material under investigation, which must be a conductive one. Specifically interesting is the meander-line-coil based Lamb wave generation, since the directivity of the waves allows a study based in the circumferential wrap-around received signal. However, the variety of defect sizes changes the behavior of the signal when it passes through the pipeline. Because of that, it is necessary to apply advanced techniques based on Smart Sound Processing (SSP). These methods involve extracting useful information from the signals sensed with EMAT at different frequencies to obtain nonlinear estimations of the depth of the defect, and to select the features that better estimate the profile of the pipeline. The proposed technique has been tested using both simulated and real signals in steel pipelines, obtaining good results in terms of Root Mean Square Error (RMSE).
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Affiliation(s)
- Joaquín García-Gómez
- Department of Signal Theory and Communications, University of Alcalá, Ctra. Madrid-Barcelona, km. 33,600, 28805 Alcalá de Henares, Spain.
| | - Roberto Gil-Pita
- Department of Signal Theory and Communications, University of Alcalá, Ctra. Madrid-Barcelona, km. 33,600, 28805 Alcalá de Henares, Spain.
| | - Manuel Rosa-Zurera
- Department of Signal Theory and Communications, University of Alcalá, Ctra. Madrid-Barcelona, km. 33,600, 28805 Alcalá de Henares, Spain.
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Bautista-Durán M, García-Gómez J, Gil-Pita R, Mohíno-Herranz I, Rosa-Zurera M. Energy-Efficient Acoustic Violence Detector for Smart Cities. INT J COMPUT INT SYS 2017. [DOI: 10.2991/ijcis.10.1.89] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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Gil-Pita R, Cuadra L, Alexandre E, Ayllón D, Alvarez L, Rosa-Zurera M. Enhancing the energy efficiency of wireless-communicated binaural hearing aids for speech separation driven by soft-computing algorithms. Appl Soft Comput 2012. [DOI: 10.1016/j.asoc.2011.03.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Vicen-Bueno R, Jarabo-Amores MP, Rosa-Zurera M, Sanz-González JL, Maldonado-Bascón S. Importance Sampling for Objective Function Estimations in Neural Detector Training Driven by Genetic Algorithms. Neural Process Lett 2010. [DOI: 10.1007/s11063-010-9155-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Flisberg A, Kjellmer I, Löfhede J, Löfgren N, Rosa-Zurera M, Lindecrantz K, Thordstein M. Does indomethacin for closure of patent ductus arteriosus affect cerebral function? Acta Paediatr 2010; 99:1493-7. [PMID: 20456268 DOI: 10.1111/j.1651-2227.2010.01857.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To study whether indomethacin used in conventional dose for closure of patent ductus arteriosus affects cerebral function measured by electroencephalograms (EEG) evaluated by quantitative measures. STUDY DESIGN Seven premature neonates with haemodynamically significant persistent ductus arteriosus were recruited. EEG were recorded before, during and after an intravenous infusion of 0.2 mg/kg indomethacin over 10 min. The EEG was analysed by two methods with different degrees of complexity for the amount of low-activity periods (LAP, "suppressions") as an indicator of affection of cerebral function. RESULTS Neither of the two methods identified any change in the amount of LAPs in the EEG as compared to before the indomethacin infusion. CONCLUSION Indomethacin in conventional dose for closure of patent ductus arteriosus does not affect cerebral function as evaluated by quantitative EEG.
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Affiliation(s)
- A Flisberg
- Department of Pediatrics, The Queen Silvia Children's Hospital Sahlgrenska University Hospital-Östra, Göteborg, Sweden.
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Löfhede J, Thordstein M, Löfgren N, Flisberg A, Rosa-Zurera M, Kjellmer I, Lindecrantz K. Automatic classification of background EEG activity in healthy and sick neonates. J Neural Eng 2010; 7:16007. [PMID: 20075506 DOI: 10.1088/1741-2560/7/1/016007] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The overall aim of our research is to develop methods for a monitoring system to be used at neonatal intensive care units. When monitoring a baby, a range of different types of background activity needs to be considered. In this work, we have developed a scheme for automatic classification of background EEG activity in newborn babies. EEG from six full-term babies who were displaying a burst suppression pattern while suffering from the after-effects of asphyxia during birth was included along with EEG from 20 full-term healthy newborn babies. The signals from the healthy babies were divided into four behavioural states: active awake, quiet awake, active sleep and quiet sleep. By using a number of features extracted from the EEG together with Fisher's linear discriminant classifier we have managed to achieve 100% correct classification when separating burst suppression EEG from all four healthy EEG types and 93% true positive classification when separating quiet sleep from the other types. The other three sleep stages could not be classified. When the pathological burst suppression pattern was detected, the analysis was taken one step further and the signal was segmented into burst and suppression, allowing clinically relevant parameters such as suppression length and burst suppression ratio to be calculated. The segmentation of the burst suppression EEG works well, with a probability of error around 4%.
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Affiliation(s)
- Johan Löfhede
- School of Engineering, University College of Borås, Borås, Sweden.
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Vicen-Bueno R, Carrasco-Álvarez R, Rosa-Zurera M, Nieto-Borge JC. Sea clutter reduction and target enhancement by neural networks in a marine radar system. Sensors (Basel) 2009; 9:1913-36. [PMID: 22573993 PMCID: PMC3345818 DOI: 10.3390/s90301913] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 02/16/2009] [Accepted: 03/11/2009] [Indexed: 11/16/2022]
Abstract
The presence of sea clutter in marine radar signals is sometimes not desired. So, efficient radar signal processing techniques are needed to reduce it. In this way, nonlinear signal processing techniques based on neural networks (NNs) are used in the proposed clutter reduction system. The developed experiments show promising results characterized by different subjective (visual analysis of the processed radar images) and objective (clutter reduction, target enhancement and signal-to-clutter ratio improvement) criteria. Moreover, a deep study of the NN structure is done, where the low computational cost and the high processing speed of the proposed NN structure are emphasized.
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Affiliation(s)
- Raúl Vicen-Bueno
- Author to whom correspondence should be addressed: E-mail: , Tel.: +34 91 885 6700, Fax: +34 91 885 6699, URL: http://ssp.uah.es/~raul
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Jarabo-Amores MP, Gil-Pita R, Rosa-Zurera M, López-Ferreras F, Vicen-Bueno R. MLP-based radar detectors for Swerling 1 targets. Pattern Recognit Image Anal 2008. [DOI: 10.1134/s1054661808010112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Gil-Pita R, Jarabo-Amores P, Rosa-Zurera M, López-Ferreras F, Utrilla-Manso M. Divide and conquer approach to improve performance on ATR systems. Pattern Recognit Image Anal 2007. [DOI: 10.1134/s1054661807020174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Saez-Landete J, Salcedo-Sanz S, Rosa-Zurera M, Alonso J, Bernabeu E. Optimal design of optical reference signals by use of a genetic algorithm. Opt Lett 2005; 30:2724-6. [PMID: 16252754 DOI: 10.1364/ol.30.002724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A new technique for the generation of optical reference signals with optimal properties is presented. In grating measurement systems a reference signal is needed to achieve an absolute measurement of the position. The optical signal is the autocorrelation of two codes with binary transmittance. For a long time, the design of this type of code has required great computational effort, which limits the size of the code to approximately 30 elements. Recently, the application of the dividing rectangles (DIRECT) algorithm has allowed the automatic design of codes up to 100 elements. Because of the binary nature of the problem and the parallel processing of the genetic algorithms, these algorithms are efficient tools for obtaining codes with particular autocorrelation properties. We design optimum zero reference codes with arbitrary length by means of a genetic algorithm enhanced with a restricted search operator.
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Affiliation(s)
- José Saez-Landete
- Departamento de Teoría de la Señal y Comunicaciones, Escuela Politécnica Superior, Universidad de Alcalá, Campus Universitario, Madrid, Spain.
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Vicen-Bueno R, Gil-Pita R, Rosa-Zurera M, Utrilla-Manso M, López-Ferreras F. Multilayer Perceptrons Applied to Traffic Sign Recognition Tasks. Computational Intelligence and Bioinspired Systems 2005. [DOI: 10.1007/11494669_106] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Vera-Candeas P, Ruiz-Reyes N, Martinez-Muñoz D, Curpian-Alonso J, Rosa-Zurera M, Lucena-Lopez MJ. Sinusoidal Modelling with Complex Exponentials for Speech and Audio Signals. Pattern Recognition and Image Analysis 2003. [DOI: 10.1007/978-3-540-44871-6_121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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