Open Access
SeTA: semiautomatic tool for annotation of eye tracking images
(ACM, 2019) Larumbe Bergera, Andoni; Porta Cuéllar, Sonia; Cabeza Laguna, Rafael; Villanueva Larre, Arantxa; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Availability of large scale tagged datasets is a must in the field of deep learning applied to the eye tracking challenge. In this paper, the potential of Supervised-Descent-Method (SDM) as a semiautomatic labelling tool for eye tracking images is shown. The objective of the paper is to evidence how the human effort needed for manually labelling large eye tracking datasets can be radically reduced by the use of cascaded regressors. Different applications are provided in the fields of high and low resolution systems. An iris/pupil center labelling is shown as example for low resolution images while a pupil contour points detection is demonstrated in high resolution. In both cases manual annotation requirements are drastically reduced.
Open Access
Effects of time-restricted eating and resistance training on skeletal muscle tissue quantity, quality and function in postmenopausal women with overweight or obesity: a study protocol
(Elsevier, 2024-12-30) Alfaro-Magallanes, Víctor Manuel; Medrano Echeverría, María; Echarte Medina, Jon; Osés Recalde, Maddi; Izquierdo Rodríguez, Claudia; Concepción Álvarez, Mara de la Caridad; Galbete Jiménez, Arkaitz; Idoate, Fernando; Zugasti Murillo, Ana; Petrina Jáuregui, María Estrella; Goñi Gironés, María Elena; Ribelles, María Jesús; Amasene, María; Arenaza Etxeberría, Lide; Tejada Garrido, Clara Isabel; Elejalde, E.; Azcárate Jiménez, Unai Xabier; Ruiz Sarrias, Oskitz; Sayar-Beristain, Onintza; García-Ramos, Amador; Martínez Labari, Cristina; Armendáriz Brugos, Cristina; Villanueva Larre, Arantxa; Ruiz, Jonatan R.; Cabeza Laguna, Rafael; Labayen Goñi, Idoia; Ciencias de la Salud; Osasun Zientziak; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
Background & aims: time-restricted eating (TRE) shows promise for weight loss and improving menopauserelated body composition and cardiometabolic health, but its effects on skeletal muscle tissue (SMT) in postmenopausal women are unknown. This study investigates the effects of three weight loss interventions over 12 weeks on SMT quantity, quality, function, and cardiometabolic health in postmenopausal women with overweight/obesity, with effects persistence evaluated at a 12-month follow-up. Methods and results: in this randomized controlled trial, 78 postmenopausal women (50–65 years; BMI 25–40 kg/m2; sedentary lifestyle; eating window ≥12 h/day; no severe metabolic impairments) will be recruited. Participants will be randomly assigned to one of three groups for 12 weeks: TRE, TRE + resistance training, or CR + resistance training. The TRE groups will reduce their eating window to 8 h and receive nutritional advice to adhere to a Mediterranean diet. The CR group will follow a personalized hypocaloric diet (− 500 kcal/day). Resistance training groups will perform supervised resistance training 3 times/week. Primary Outcome: Change in SMT quantity measured by MRI at baseline and after 12 weeks. Secondary Outcomes: intermuscular adipose tissue (IMAT), strength, power, body weight and composition, and cardiometabolic risk factors. Conclusion: this study will illustrate the effects of TRE and TRE combined with resistance exercise compared with the currently recommended obesity-lifestyle treatment on SMT quantity, quality, function, and cardiometabolic markers. The results will offer insights into dietary strategies to combat obesity and metabolic diseases without increasing sarcopenia risk in postmenopausal women, a sparsely studied and particularly affected population.
Open Access
Low cost gaze estimation: knowledge-based solutions
(IEEE, 2020) Martinikorena Aranburu, Ion; Larumbe Bergera, Andoni; Ariz Galilea, Mikel; Porta Cuéllar, Sonia; Cabeza Laguna, Rafael; Villanueva Larre, Arantxa; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Eye tracking technology in low resolution scenarios is not a completely solved issue to date. The possibility of using eye tracking in a mobile gadget is a challenging objective that would permit to spread this technology to non-explored fields. In this paper, a knowledge based approach is presented to solve gaze estimation in low resolution settings. The understanding of the high resolution paradigm permits to propose alternative models to solve gaze estimation. In this manner, three models are presented: a geometrical model, an interpolation model and a compound model, as solutions for gaze estimation for remote low resolution systems. Since this work considers head position essential to improve gaze accuracy, a method for head pose estimation is also proposed. The methods are validated in an optimal framework, I2Head database, which combines head and gaze data. The experimental validation of the models demonstrates their sensitivity to image processing inaccuracies, critical in the case of the geometrical model. Static and extreme movement scenarios are analyzed showing the higher robustness of compound and geometrical models in the presence of user’s displacement. Accuracy values of about 3◦ have been obtained, increasing to values close to 5◦ in extreme displacement settings, results fully comparable with the state-of-the-art.
Open Access
Effects of a family-based lifestyle intervention plus supervised exercise training on abdominal fat depots in children with overweight or obesity: a secondary analysis of a nonrandomized clinical trial
(American Medical Association, 2022) Cadenas-Sánchez, Cristina; Cabeza Laguna, Rafael; Idoate, Fernando; Osés Recalde, Maddi; Medrano Echeverría, María; Villanueva Larre, Arantxa; Arenaza Etxeberría, Lide; Sanz Muñoz, Aritz; Ortega, Francisco B.; Ruiz, Jonatan R.; Labayen Goñi, Idoia; Ciencias de la Salud; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Institute of Smart Cities - ISC; Osasun Zientziak; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Importance Excess abdominal fat is a major determinant in the development of insulin resistance and other metabolic disorders. Increased visceral adipose tissue (VAT) seems to precede the development of insulin resistance and is therefore a prime target of childhood lifestyle interventions aimed at preventing diabetes. OBJECTIVES To examine the effect of added exercise to a family-based lifestyle intervention program designed to reduce VAT plus subcutaneous (ASAT), intermuscular (IMAAT), and pancreatic (PAT) adipose tissue in children with overweight or obesity and to explore the effect of changes in VAT on insulin resistance. DESIGN, SETTING, AND PARTICIPANTS This 2-group, parallel-design clinical trial was conducted in Vitoria-Gasteiz, Spain. A total of 116 children with overweight or obesity participated and were assigned to a 22-week family-based lifestyle program (control group [n = 57]) or the same program plus an exercise intervention (exercise group [n = 59]). Data were collected between September 1, 2014, and June 30, 2017, and imaging processing for fat depot assessments and data analysis were performed between May 1, 2019, and February 12, 2021. INTERVENTIONS The compared interventions consisted of a family-based lifestyle and psychoeducation program (two 90-minute sessions per month) and the same program plus supervised exercise (three 90-minute sessions per week). MAIN OUTCOMES AND MEASURES The primary outcome of this study was the change in VAT between baseline and 22 weeks as estimated by magnetic resonance imaging. The secondary outcomes were changes in ASAT, IMAAT, and PAT. The effect of changes in VAT area on insulin resistance was also recorded. RESULTS The 116 participants included in the analysis (62 girls [53.4%]) had a mean (SD) age of 10.6 (1.1) years, and 67 (57.8%) presented with obesity. Significantly greater reductions were recorded for the exercise group in terms of reduction in VAT (−18.1% vs −8.5% for the control group; P = .004), ASAT (−9.9% vs −3.0%; P = .001), and IMAAT (−6.0% vs −2.6%; P = .02) fat fractions compared with the control group. Changes in VAT explained 87.6% of the improvement seen in insulin resistance (β = −0.102 [95% CI, −0.230 to −0.002]). CONCLUSIONS AND RELEVANCE These findings suggest that the addition of exercise to a lifestyle intervention program substantially enhanced the positive effects on abdominal fat depots in children with overweight or obesity. In addition, the reduction in VAT seemed to largely mediate the improvement of insulin sensitivity. These results highlight the importance of including exercise as part of lifestyle therapies aimed at treating childhood obesity and preventing the development of type 2 diabetes.
Open Access
Gaze tracking system model based on physical parameters
(World Scientific Publishing, 2007) Villanueva Larre, Arantxa; Cabeza Laguna, Rafael; Porta Cuéllar, Sonia; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In the past years, research in eye tracking development and applications has attracted much attention and the possibility of interacting with a computer employing just gaze information is becoming more and more feasible. Efforts in eye tracking cover a broad spectrum of fields, system mathematical modeling being an important aspect in this research. Expressions relating to several elements and variables of the gaze tracker would lead to establish geometric relations and to find out symmetrical behaviors of the human eye when looking at a screen. To this end a deep knowledge of projective geometry as well as eye physiology and kinematics are basic. This paper presents a model for a bright-pupil technique tracker fully based on realistic parameters describing the system elements. The system so modeled is superior to that obtained with generic expressions based on linear or quadratic expressions. Moreover, model symmetry knowledge leads to more effective and simpler calibration strategies, resulting in just two calibration points needed to fit the optical axis and only three points to adjust the visual axis. Reducing considerably the time spent by other systems employing more calibration points renders a more attractive model.
Open Access
Robust and accurate 2D-tracking-based 3D positioning method: application to head pose estimation
(Elsevier, 2019) Ariz Galilea, Mikel; Villanueva Larre, Arantxa; Cabeza Laguna, Rafael; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Head pose estimation (HPE) is currently a growing research field, mainly because of the proliferation of human–computer interfaces (HCI) in the last decade. It offers a wide variety of applications, including human behavior analysis, driver assistance systems or gaze estimation systems. This article aims to contribute to the development of robust and accurate HPE methods based on 2D tracking of the face, enhancing performance of both 2D point tracking and 3D pose estimation. We start with a baseline method for pose estimation based on POSIT algorithm. A novel weighted variant of POSIT is then proposed, together with a methodology to estimate weights for the 2D–3D point correspondences. Further, outlier detection and correction methods are also proposed in order to enhance both point tracking and pose estimation. With the aim of achieving a wider impact, the problem is addressed using a global approach: all the methods proposed are generalizable to any kind of object for which an approximate 3D model is available. These methods have been evaluated for the specific task of HPE using two different head pose video databases; a recently published one that reflects the expected performance of the system in current technological conditions, and an older one that allows an extensive comparison with state-of-the-art HPE methods. Results show that the proposed enhancements improve the accuracy of both 2D facial point tracking and 3D HPE, with respect to the implemented baseline method, by over 15% in normal tracking conditions and over 30% in noisy tracking conditions. Moreover, the proposed HPE system outperforms the state of the art on the two databases.
Open Access
Development of a prediction protocol for the screening of metabolic associated fatty liver disease in children with overweight or obesity
(Wiley, 2022) Osés Recalde, Maddi; Cadenas-Sánchez, Cristina; Medrano Echeverría, María; Galbete Jiménez, Arkaitz; Miranda Ferrúa, Emiliano; Ruiz, Jonatan R.; Sánchez-Valverde, Félix; Ortega, Francisco B.; Cabeza Laguna, Rafael; Villanueva Larre, Arantxa; Idoate, Fernando; Labayen Goñi, Idoia; Osasun Zientziak; Institute of Smart Cities - ISC; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Ciencias de la Salud; Gobierno de Navarra / Nafarroako Gobernua
Background: the early detection and management of children with metabolic associ-ated fatty liver disease (MAFLD) is challenging. Objective: to develop a non-invasive and accurate prediction protocol for the identi-fication of MAFLD among children with overweight/obesity candidates to confirma-tory diagnosis. Methods: a total of 115 children aged 8–12 years with overweight/obesity, rec-ruited at a primary care, were enrolled in this cross-sectional study. The external vali-dation was performed using a cohort of children with overweight/obesity (N=46)aged 8.5–14.0 years. MAFLD (≥5.5% hepatic fat) was diagnosed by magnetic reso-nance imaging (MRI). Fasting blood biochemical parameters were measured, and25 candidates’ single nucleotide polymorphisms (SNPs) were determined. Variablespotentially associated with the presence of MAFLD were included in a multivariatelogistic regression. Results: children with MAFLD (36%) showed higher plasma triglycerides (TG),insulin, homeostasis model assessment ofinsulin resistance (HOMA-IR), alanineaminotransferase (ALT), aspartate transaminase (AST), glutamyl-transferase (GGT)and ferritin (p< 0.05). The distribution of the risk-alleles of PPARGrs13081389, PPARGrs1801282, HFErs1800562 and PNLPLA3rs4823173 was significantly different between children with and without MAFLD (p<0.05). Threebiochemical- and/or SNPs-based predictive models were developed, showingstrong discriminatory capacity (AUC-ROC: 0.708–0.888) but limited diagnosticperformance (sensitivity 67%–82% and specificity 63%–69%). A prediction proto-col with elevated sensitivity (72%) and specificity (84%) based on two consecutive steps was developed. The external validation showed similar results: sensitivity of 70% and specificity of 85%. Conclusions: the HEPAKID prediction protocol is an accurate, easy to implant, minimally invasive and low economic cost tool useful for the early identification and management of paediatric MAFLD in primary care.
Open Access
Differences in specific abdominal fat depots between metabolically healthy and unhealthy children with overweight/obesity: the role of cardiorespiratory fitness
(Wiley, 2023) Cadenas-Sánchez, Cristina; Medrano Echeverría, María; Villanueva Larre, Arantxa; Cabeza Laguna, Rafael; Idoate, Fernando; Osés Recalde, Maddi; Rodríguez Vigil, Beatriz; Álvarez de Eulate, Natalia; Alberdi Aldasoro, Nerea; Ortega, Francisco B.; Labayen Goñi, Idoia; Ciencias de la Salud; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Institute of Smart Cities - ISC; Osasun Zientziak; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Objectives: Fat depots localization has a critical role in the metabolic health status of adults. Nevertheless, whether that is also the case in children remains under- studied. Therefore, the aims of this study were: (i) to examine the differ-ences between metabolically healthy (MHO) and unhealthy (MUO) overweight/obesity phenotypes on specific abdominal fat depots, and (ii) to further explore whether cardiorespiratory fitness plays a major role in the differences between metabolic phenotypes among children with overweight/obesity. Methods: A total of 114 children with overweight/obesity (10.6 ±1.1 years, 62 girls) were included. Children were classified as MHO (n=68) or MUO. visceral (VAT), abdominal subcutaneous (ASAT), intermuscular abdominal (IMAAT), psoas, hepatic, pancreatic, and lumbar bone marrow adipose tissues were measured by magnetic resonance imaging. Cardiorespiratory fitness was assessed using the 20 m shuttle run test. Results: MHO children had lower VAT and ASAT contents and psoas fat fraction compared to MUO children (difference =12.4%– 25.8%, all p<0.035). MUO- unfit had more VAT and ASAT content than those MUO- fit and MHO- fit (difference =34.8%– 45.3%, all p<0.044). MUO- unfit shows also greater IMAAT fat fraction than those MUO- fit and MHO- fit peers (difference =16.4%– 13.9% respectively, all p≤0.001). In addition, MHO- unfit presented higher IMAAT fat fraction than MHO- fit (difference =13.4%, p<0.001). MUO- unfit presented higher psoas fat fraction than MHO- fit (difference =29.1%, p=0.008). Conclusions: VAT together with ASAT and psoas fat fraction, were lower in MHO than in MUO children. Further, we also observed that being fit, regardless of metabolic phenotype, has a protective role over the specific abdominal fat depots among children with overweight/obesity.
Open Access
Models for gaze tracking systems
(Hindawi Publishing Corporation, 2007) Villanueva Larre, Arantxa; Cabeza Laguna, Rafael; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
One of the most confusing aspects that one meets when introducing oneself into gaze tracking technology is the wide variety, in terms of hardware equipment, of available systems that provide solutions to the same matter, that is, determining the point the subject is looking at. The calibration process permits generally adjusting nonintrusive trackers based on quite different hardware and image features to the subject. The negative aspect of this simple procedure is that it permits the system to work properly but at the expense of a lack of control over the intrinsic behavior of the tracker. The objective of the presented article is to overcome this obstacle to explore more deeply the elements of a video-oculographic system, that is, eye, camera, lighting, and so forth, from a purely mathematical and geometrical point of view. The main contribution is to find out the minimum number of hardware elements and image features that are needed to determine the point the subject is looking at. A model has been constructed based on pupil contour and multiple lighting, and successfully tested with real subjects. On the other hand, theoretical aspects of video-oculographic systems have been thoroughly reviewed in order to build a theoretical basis for further studies.
Open Access
Fast and robust ellipse detection algorithm for head-mounted eye tracking systems
(Springer, 2018) Martinikorena Aranburu, Ion; Cabeza Laguna, Rafael; Villanueva Larre, Arantxa; Urtasun, Iñaki; Larumbe Bergera, Andoni; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In head-mounted eye tracking systems, the correct detection of pupil position is a key factor in estimating gaze direction. However, this is a challenging issue when the videos are recorded in real-world conditions, due to the many sources of noise and artifacts that exist in these scenarios, such as rapid changes in illumination, reflections, occlusions and an elliptical appearance of the pupil. Thus, it is an indispensable prerequisite that a pupil detection algorithm is robust in these challenging conditions. In this work, we present one pupil center detection method based on searching the maximum contribution point to the radial symmetry of the image. Additionally, two different center refinement steps were incorporated with the aim of adapting the algorithm to images with highly elliptical pupil appearances. The performance of the proposed algorithm is evaluated using a dataset consisting of 225,569 head-mounted annotated eye images from publicly available sources. The results are compared with the better algorithm found in the bibliography, with our algorithm being shown as superior.