A stacked autoencoder-based aid system for severity degree classification of knee ligament rupture.

BACKGROUND: Knee ligament rupture is one of the most common injuries, but the diagnosis of its severity tends to require the use of complex methods and analyses that are not always available to patients. AIM: The objective of this research is the investigation and development of a diagnostic aid system to analyze and determine patterns that characterize the presence of the injury and its degree of severity. METHODS: Implement a novel proposal of a framework based on stacked auto-encoder (SAE) for ground reaction force (GRF) signals analysis, coming from the GaitRec database. Analysis of the raw data is used to determine the main features that allow us to diagnose the presence of a knee ligament rupture and classify its severity as high, mid or mild. RESULTS: The process is divided into two stages to determine the presence of the lesion and, if necessary, evaluate variations in features to classify the degree of severity as high, mid, and mild. The framework presents an accuracy of 87 % and a F1-Score of 90 % for detecting ligament rupture and an accuracy of 86.5 % and a F1-Score of 87 % for classifying severity. CONCLUSION: This new methodology aims to demonstrate the potential of SAE in physiotherapy applications as an evaluation and diagnostic tool, identifying irregularities associated with ligament rupture and its degree of severity, thus providing updated information to the specialist during the rehabilitation process.

Defining the limits of the anterior wall of the cavernous sinus through an endoscopic view: Cadaveric anatomical study.

Background: The anterior wall of the cavernous sinus (CS) represents an important landmark for endoscopic surgery that although mentioned before, no precise anatomical boundaries have been described. We describe the anatomical landmarks that delimit the anterior wall of the CS, emphasizing its importance as a reference for accessing the CS through endoscopic approaches. Methods: Six adult cadaveric heads fixed with formaldehyde and injected with colored silicone were studied. In all the heads, an endonasal endoscopic approach to the sellar and parasellar regions was performed and the anatomy of the anterior wall of the CS was studied. Results: Four consistent anatomical landmarks that mark the limits of the anterior wall of the CS were found in all the specimens: anterosuperiorly, the lateral opticocarotid recess; posterosuperiorly, the medial opticocarotid recess; anteroinferiorly, the inferior part of the maxillary strut; and posteroinferiorly, the superolateral angle of the clival recess. Conclusion: It is of paramount importance to recognize the anatomical landmarks that define the limits of the anterior wall of the CS to achieve a safe access to this so complex region.

Short-Term Thermal Effect of Continuous Ultrasound from 3 MHz to 1 and 0.5 W/cm2 Applied to Gastrocnemius Muscle.

Continuous ultrasound is recognized for its thermal effect and use in the tissue repair process. However, there is controversy about its dosage and efficacy. This study used infrared thermography, a non-invasive technique, to measure the short-term thermal effect of 3 MHz continuous ultrasound vs. a placebo, referencing the intensity applied. It was a single-blind, randomized clinical trial of 60 healthy volunteers (19-24 years old) divided into three equal groups. Group 1:1 W/cm2 for 5 min; Group 2: 0.5 W/cm2 for 10 min; and Group 3: the placebo for 5 min. The temperature was recorded through five thermographic images per patient: pre- and post-application, 5, 10, and 15 min later. After statistical analysis, a more significant decrease in temperature (p<0.05 ) was observed in the placebo group compared with the remaining groups after the application of continuous ultrasound. Group 1 was the one that generated the highest significant thermal effect (p<0.001), with an increase of 3.05 °C at 15 min, compared with the other two groups. It is concluded that to generate a thermal effect in the muscle, intensities of ≥1 W/cm2 are required, since the dosage maintained a temperature increase for more than 5 min.

Relative cerebral blood volume as response predictor in the treatment of recurrent glioblastoma with anti-angiogenic therapy.

BACKGROUND: Glioblastoma is one of the most common brain tumors in adult populations, usually carrying a poor prognosis. While several studies have researched the impact of anti-angiogenic therapies, especially anti-VEFG treatments in glioblastoma, few have attempted to assess its progress using imaging studies. PURPOSE: We attempted to analyze whether relative cerebral blood volume (rCBV) from dynamic susceptibility-weighted contrast-enhanced MRI (DSC-MRI) could predict response in patients with glioblastoma undergoing Bevacizumab (BVZ) treatment. METHODS: We performed a retrospective study evaluating patients with recurrent glioblastoma receiving anti-angiogenic therapy with BVZ between 2012 and 2017 in our institution. Patients were scheduled for routine MRIs at baseline and first-month follow-up visits. Studies were processed for DSC-MRI, cT1, and FLAIR images, from which relative cerebral blood volume measurements were obtained. We assessed patient response using the Response Assessment in Neuro-Oncology (RANO) working group criteria and overall survival. RESULTS: 40 patients were included in the study and were classified as Bevacizumab responders and non-responders. The average rCBV before treatment was 4.5 for both groups, and average rCBV was 2.5 for responders and 5.4 for non-responders. ROC curve set a cutoff point of 3.7 for rCBV predictive of response to BVZ. Cox Multivariate analysis only showed rCBV as a predictive factor of OS. CONCLUSION: A statistically significant difference was found in rCBV between patients who responded and those who did not respond to BVZ treatment. rCBV may be a low-cost and effective marker to assess response to Bevacizumab treatment in GBM.

Immunohistochemical Expression of Ki-67, Dopamine D1 and Dopamine D2 Receptors in Meningiomas in a Tertiary Institution in Mexico.

Objectives Meningiomas (MNGs) are the most common intracranial tumors found in the adult population. While most intracranial MNGs may be surgically removed, a subset of patients remains ineligible for conventional treatment. This is either because of a lack of surgical access or due to atypical, anaplastic or invasive characteristics of the tumors. These patients may benefit from targeted therapies that focus on cell receptor expression. The aim of this study was to assess dopamine receptor (DR) and Ki-67 expression in the MGNs of patients treated with surgery in the Instituto Nacional de Neurología y Neurocirugía, Mexico. Materials and methods This study analyzed 23 patients with confirmed MNG diagnoses (10 female and 13 male (mean age: 44.5 years)) who had undergone surgical resection between 2010 and 2014 at our institution. In the collected samples, we performed analyses for Ki-67, Dopamine 1 and Dopamine 2 receptors' expression. Results For the markers Ki-67, DR-D1 and DR-D2, the mean percentual expressions were 18.9%, 23.02% and 8.33%. No significant correlation was found between the expressions of these receptors and the studied MNG characteristics. The expression index of Ki-67 showed a significant relation with mean age (p = 0.03) and prolactin levels (p = 0.02). Conclusions Samples showed varied expressions of the studied receptors. Despite the difference in expressions between the markers, more studies are needed to confirm the findings. In contrast to previous studies, we could not find any relationship between D2-R and tumor characteristics.

Epidemiology of Intracranial Meningiomas in Mexico: Cohort of the National Institute of Neurology and Neurosurgery During the Last Decade.

Introduction Meningiomas have been described as slow-growing neoplasms with benign behavior derived from the connective tissue surrounding the brain and spinal cord. Meningiomas represent one-third of primary central nervous system (CNS) tumors. The World Health Organization (WHO) initially classified them into three groups based on their histopathological characteristics, recently incorporating molecular patterns. Small cohorts have been reported in Latin America compared to the international literature. Ignoring the epidemiology of meningiomas in this region and considering this limitation, we aim to study the epidemiology of meningiomas in our country, Mexico. Material and methods A historical cohort was carried out on 916 patients diagnosed with intracranial meningiomas from January 2008 to January 2021, considering sociodemographic, topographic, and histopathological characteristics. Results In this study, 69.4% (n=636) of patients were women with a mean overall age of 47.53 (SD=14.85) years; 79.6% (n=729) of the lesions were supratentorial with convexity meningiomas being the most prevalent at 32.6% (n=299). Histopathologically, transitional (45.7%) (n=419), meningothelial (22.1%) (n=202), and fibroblastic (16.7%) (n=153) meningiomas were the most frequent. We found significant differences between men and women in age (p=0.01), infra or supratentorial presentation (p<0.001), location of the lesion (p<0.001), and histopathological characteristics (p<0.001). Conclusions Our results are consistent with what has been reported; however, until now, it appears as the largest series reported in our country and Latin America.

Cholesterol goals, statin use and residual cardiovascular risk estimated by SMART score: Study of a Nicaraguan population.

Introduction: Adverse cardiovascular events that arise in patients with established cardiovascular disease have prompted researchers to seek variables that can help estimate residual cardiovascular risk and aid in its reduction. In Latin-America, there is limited data assessing this type of risk. Objective: Estimate residual cardiovascular risk in ambulatory patients diagnosed with Chronic Coronary Syndrome (CCS) using the SMART-Score scale seen at five clinics in Nicaragua; determine the prevalence of patients that achieve a serum LDL level of <55 mg/dL; and describe the use of statins in these patients. Methods: A total of 145 participants previously diagnosed with CCS seen regularly in ambulatory visits were enrolled. A survey was completed, including epidemiological variables that allowed the calculation of a SMART score. Data analysis was conducted using SPSS version 21.0. Results: A 46.2% of participants were male, the average age was 68.7 years (11.4 SD), 91% had hypertension, 80.7% had a BMI ≥25. Under the SMART Score risk classification per Dorresteijn et al. the following risk distribution was found: 2.8% low, 31% moderate, 20% high, 13.1% very high and 33.1% extremely high. Per the risk classification of Kaasenbrood et al., 2.8% were in the 0-9% group, 31% in the 10-19%, 20% in 20-29% and 46.2% were in the ≥30% group. A 64.8% did not meet LDL goals. Conclusion: There is an inadequate control of cLDL levels in patients with CCS, and the appropriate available therapeutic resources aren't being utilized. It is important to achieve a proper control of lipid levels in order to improve cardiovascular outcomes, despite currently being far from these goals.

Knee skin temperature response of patients with bilateral patellofemoral syndrome before and after heat and cold stress.

Patellofemoral Pain Syndrome is characterized by the presence of pain in the front area of the knee, which occurs when performing common activities such as climbing stairs, and bending the knees, among others. The objective of this research was to evaluate the detection capability of infrared thermography in patients with Patellofemoral Pain Syndrome, in the baseline state, as well as after the application of thermal stress. The investigation was conducted in 48 patients, who were subdivided into four groups (n = 12). Two subgroups were healthy patients and two with Patellofemoral Pain Syndrome. For the diagnosis of the syndrome, a manual evaluation was performed using the Zohlen test and Q angle measurement. Subsequently, cold stress was applied for 10 min to a healthy subgroup and an experimental subgroup. The remaining two subgroups were subjected to heat stress for 15 min. Thermographic images of the lower extremities were acquired at seven time points, at baseline, immediately after application of thermal stress and then every 3 min until 15 min were completed. It was observed that patients presented Patellofemoral Pain Syndrome bilaterally. After statistical analysis, it was found that there were no significant differences in baseline temperature between the groups. However, for heat stress, a higher temperature was observed in the group with Patellofemoral Pain Syndrome (p < 0.05) in the recovery period, and in the case of cold stress, only a lower temperature in the left knee immediately after the application. In conclusion, it is not possible to detect patellofemoral syndrome bilaterally in the baseline state by thermography and neither is it evident in cold stress. However, after heat stress, thermal recovery is lower for the PFPS group, so it would be susceptible to detection.

Gene Expression Behavior of a Set of Genes in Platelet and Tissue Samples from Patients with Breast Cancer.

The tumor microenvironment (TME) is constituted by a great diversity of highly dynamic cell populations, each of which contributes ligands, receptors, soluble proteins, mRNAs, and miRNAs, in order to regulate cellular activities within the TME and even promote processes such as angiogenesis or metastasis. Intravasated platelets (PLT) undergo changes in the TME that convert them into tumor-educated platelets (TEP), which supports the development of cancer, angiogenesis, and metastasis through the degranulation and release of biomolecules. Several authors have reported that the deregulation of PF4, VEGF, PDGF, ANG-1, WASF3, LAPTM4B, TPM3, and TAC1 genes participates in breast cancer progression, angiogenesis, and metastasis. The present work aimed to analyze the expression levels of this set of genes in tumor tissues and platelets derived from breast cancer patients by reverse transcription-quantitative polymerase chain reaction (RTqPCR) assays, in order to determine if there was an expression correlation between these sources and to take advantage of the new information to be used in possible diagnosis by liquid biopsy. Data from these assays showed that platelets and breast cancer tumors present similar expression levels of a subset of these genes' mRNAs, depending on the molecular subtype, comorbidities, and metastasis presence.

Obstructive Hydrocephalus Due to Posterior Fossa Tumors in Adults: A Comparative Analysis of 3 Surgical Techniques.

BACKGROUND: The main treatments for hydrocephalus due to posterior fossa tumors are tumor resection with or without an external ventricular drain, ventriculoperitoneal shunt (VPS), and endoscopic third ventriculostomy. Although preoperative cerebrospinal fluid diversion by any of these techniques improves clinical outcomes, evidence comparing the efficacy of these techniques is scarce. Therefore, we aimed to retrospectively evaluate each treatment modality. METHODS: This single-center study analyzed 55 patients. Treatments were classified as successful (hydrocephalus resolution with a single surgical event) or failed and compared with a χ2 test. Kaplan-Meier curves and log-rank tests were employed. A Cox proportional hazard model was used to determine relevant covariates predicting outcomes. RESULTS: Mean patient age was 36.3 years, 43.4% of patients were men, and 50.9% of patients presented with uncompensated intracranial hypertension. Mean tumor volume was 33.4 cm3, and extent of resection was 90.85%. Tumor resection with or without an external ventricular drain was successful in 58.82% of cases, VPS was successful in 100%, and endoscopic third ventriculostomy was successful in 76.19% (P = 0.014). Mean follow-up time was 15.12 months. Log-rank test found statistically significant differences between survival curves of treatments (P = 0.016) favoring the VPS group. Postoperative surgical site hematoma was a significant covariate in the Cox model (hazard ratio = 17; 95% confidence ratio, 2.301-81.872; P = 0.004). CONCLUSIONS: This study favored VPS as the most reliable treatment of hydrocephalus due to posterior fossa tumors in adult patient; however, several factors influence clinical outcomes. We proposed an algorithm based on our findings and other authors' findings to facilitate the decision-making process.

Automatic Segmentation of Facial Regions of Interest and Stress Detection Using Machine Learning.

Stress is a factor that affects many people today and is responsible for many of the causes of poor quality of life. For this reason, it is necessary to be able to determine whether a person is stressed or not. Therefore, it is necessary to develop tools that are non-invasive, innocuous, and easy to use. This paper describes a methodology for classifying stress in humans by automatically detecting facial regions of interest in thermal images using machine learning during a short Trier Social Stress Test. Five regions of interest, namely the nose, right cheek, left cheek, forehead, and chin, are automatically detected. The temperature of each of these regions is then extracted and used as input to a classifier, specifically a Support Vector Machine, which outputs three states: baseline, stressed, and relaxed. The proposal was developed and tested on thermal images of 25 participants who were subjected to a stress-inducing protocol followed by relaxation techniques. After testing the developed methodology, an accuracy of 95.4% and an error rate of 4.5% were obtained. The methodology proposed in this study allows the automatic classification of a person's stress state based on a thermal image of the face. This represents an innovative tool applicable to specialists. Furthermore, due to its robustness, it is also suitable for online applications.

A DFT Study of the Reaction of Acrylamide with L-Cysteine and L-Glutathione.

Thermal processing of certain foods implies the formation of acrylamide, which has been proven to provoke adverse effects on human health. Thus, several strategies to mitigate it have been developed. One of them could be the application of organosulfur compounds obtained from natural sources to react with the acrylamide, forming non-toxic adducts. A DFT study of the acrylamide reaction with the organosulfur model compounds L-cysteine and L-glutathione by Michael addition and a free radical pathway complemented by a kinetic study of these model molecules has been applied. The kinetic evaluation results demonstrate that the L-glutathione reaction exhibited a higher rate constant than the other studied compound.

Characteristics and Long-Term Outcome of Cerebellar Strokes in a Single Health Care Facility in Mexico.

Objective The purpose of this study was to analyze and discuss the clinical characteristics, long-term outcome, and prognostic factors of cerebellar strokes treated in a single health care facility in Mexico. Methods We retrospectively reviewed the medical records of adult patients admitted to our hospital with diagnosis of cerebellar ischemic and hemorrhagic stroke between 2018 and 2020. Baseline data included sociodemographic and radiological variables, treatment (surgical versus conservative), and Glasgow Coma Scale on arrival (GCSOA). The final neurological outcome was evaluated with the Glasgow Outcome Scale (GOS) six months after hospital discharge. Results Ten patients (seven male and three female) with a mean age of 57.9 ± 9.3 years were included, six with cerebellar ischemic infarction and four with cerebellar hemorrhage. Out of the 10 patients, four underwent surgery (suboccipital decompressive craniectomy {SDC} ± ventriculostomy). The outcome was favorable in four cases (40%) and unfavorable in six (60%). Patients who underwent surgical treatment fared worse with all four cases associating poor outcome. The comparison between good and poor outcome groups showed significant differences in the presence of obstructive hydrocephalus (one versus six, p = 0.05) and poorer GCSOA (6.16 ± 1.72 versus 12.5 ± 3.6, p = 0.05), associating poorer outcome. Conclusion There is still controversy regarding the appropriate management of cerebellar strokes. The presence of obstructive hydrocephalus and poorer GCSOA are associated to worse outcomes.

QSTR Modeling to Find Relevant DFT Descriptors Related to the Toxicity of Carbamates.

Compounds containing carbamate moieties and their derivatives can generate serious public health threats and environmental problems due their high potential toxicity. In this study, a quantitative structure-toxicity relationship (QSTR) model has been developed by using one hundred seventy-eight carbamate derivatives whose toxicities in rats (oral administration) have been evaluated. The QSRT model was rigorously validated by using either tested or untested compounds falling within the applicability domain of the model. A structure-based evaluation by docking from a series of carbamates with acetylcholinesterase (AChE) was carried out. The toxicity of carbamates was predicted using physicochemical, structural, and quantum molecular descriptors employing a DFT approach. A statistical treatment was developed; the QSRT model showed a determination coefficient (R2) and a leave-one-out coefficient (Q2LOO) of 0.6584 and 0.6289, respectively.

Diagnostic Strategies for Breast Cancer Detection: From Image Generation to Classification Strategies Using Artificial Intelligence Algorithms.

Breast cancer is one the main death causes for women worldwide, as 16% of the diagnosed malignant lesions worldwide are its consequence. In this sense, it is of paramount importance to diagnose these lesions in the earliest stage possible, in order to have the highest chances of survival. While there are several works that present selected topics in this area, none of them present a complete panorama, that is, from the image generation to its interpretation. This work presents a comprehensive state-of-the-art review of the image generation and processing techniques to detect Breast Cancer, where potential candidates for the image generation and processing are presented and discussed. Novel methodologies should consider the adroit integration of artificial intelligence-concepts and the categorical data to generate modern alternatives that can have the accuracy, precision and reliability expected to mitigate the misclassifications.

Platelet Membrane: An Outstanding Factor in Cancer Metastasis.

In addition to being biological barriers where the internalization or release of biomolecules is decided, cell membranes are contact structures between the interior and exterior of the cell. Here, the processes of cell signaling mediated by receptors, ions, hormones, cytokines, enzymes, growth factors, extracellular matrix (ECM), and vesicles begin. They triggering several responses from the cell membrane that include rearranging its components according to the immediate needs of the cell, for example, in the membrane of platelets, the formation of filopodia and lamellipodia as a tissue repair response. In cancer, the cancer cells must adapt to the new tumor microenvironment (TME) and acquire capacities in the cell membrane to transform their shape, such as in the case of epithelial-mesenchymal transition (EMT) in the metastatic process. The cancer cells must also attract allies in this challenging process, such as platelets, fibroblasts associated with cancer (CAF), stromal cells, adipocytes, and the extracellular matrix itself, which limits tumor growth. The platelets are enucleated cells with fairly interesting growth factors, proangiogenic factors, cytokines, mRNA, and proteins, which support the development of a tumor microenvironment and support the metastatic process. This review will discuss the different actions that platelet membranes and cancer cell membranes carry out during their relationship in the tumor microenvironment and metastasis.

Validación de la Escala Breve de Optimismo Interactivo-G en México antes de la COVID-19 / Validation of the Brief Interactive Optimism Scale-G in Mexico before COVID-19 / Validação da Escala Breve de Otimismo Interativo-G no méxico antes do COVID-19

Resumen Los objetivos primarios del presente estudio fueron determinar la validez de constructo, convergente y discriminante de la Escala Breve de Optimismo Interactivo-G (EBOI-G), en participantes de seis estados de México y calcular su consistencia interna. Participaron 3 289 mexicanos, 2 028 hombres y 1 243 mujeres (18 casos no contestaron cuál era su género). Su edad promedio = 30.43 años, DE = 10.52. Se usó el análisis factorial confirmatorio y análisis de regresión múltiple, y se encontraron buenos indicadores promedio de bondad de ajuste (e. g., CFI = .99; RMSEA = .07.). Se evaluó la validez convergente, r (3 289) = .52 (p = < .01; d = mediano), con la Escala de Satisfacción con la Vida. Se estimó la validez discriminante, r (3 289) r = -.19, con la Escala Breve de Disposición a la Ira (p = < .01; d = casi pequeño). El alfa = .70 (3 289); p = < .01; el omega = .76. Se concluye que hay evidencia parcial nacional que apoya el uso de la EBOI-G, debido a la carencia de una medida de este tipo en México, útil cuando menos para propósitos de investigación.

Abstract The primary objectives of this study were determining the construct, convergent, and discriminant validity of the Brief Interactive Optimism Scale-G (BIOS-G) in participants from six states of Mexico and estimating its internal consistency. In this study 3289 Mexicans participated (2028 men and 1243 women). The average age was = 30.43 years and SD = 10.52. Confirmatory factor analysis (CFA) and multiple regression analysis (MRA) were applied. There were appropriate fit indexes (e. g., CFI = .99; RMSEA = .07.). Convergent validity showed an r (3289) = .52 (p = < .01; d = medium), with the Satisfaction with Life Scale (SWLS) and the estimation of discriminant validity was r (3 289) r = -.19 with the Brief Scale for Assessing Anger Proneness (APS-G) (p = < .01; d = almost small), Alpha = .70 (3 289); p = < .01; omega = .76. The conclusion is that there is partial national evidence supporting the use of BIOS-G, because Mexico lacks a measure of this kind, being useful, at least, for research purposes.

Resumo Os objetivos primários do estudo foram determinar a validade convergente e discriminante do construto da Escala Breve de Otimismo Interativo-G (EBOI-G), em participantes de seis estados do México e calcular sua consistência interna. Participaram 3 289 mexicanos, sendo 2 028 homens e 1 243 mulheres. A média de idade foi = 30.43 anos, DP = 10.52. Foram utilizadas análises fatoriais confirmatórias e análises de regressão múltipla. Bons indicadores médios de qualidade de ajuste foram encontrados (por exemplo, CFI = .99; RMSEA = .07.) A validade convergente foi avaliada, r (3 289) = .52 (p = <.01; d = mediana), com a Escala de satisfação com a vida. A validade discriminante, r (3 289) = -.19 foi estimada com a Escala Breve de Disposição à Raiva (p = <.01; d = quase pequeno). O alfa = 0,70 (3 289); p = <0,01; o ômega = 0,76. Conclui-se que há evidências nacionais parciais que apoiam o uso da EBOI-G, devido à falta de uma medida desse tipo no México, sendo útil pelo menos para fins de pesquisa.

The chemical reactivity and QSPR of organic compounds applied to dye-sensitized solar cells using DFT.

The structural and electronic properties were calculated for seventy organic compounds used as dye sensitizers in solar cells, applying the B3LYP exchange-correlation energy functional with the 6-311G∗∗ basis set. Moreover, the present study proposes two new quantitative structure-property relationship (QSPR) models that enable the prediction of the power conversion efficiency (PCE) and maximum absorption wavelength (λmax) of these systems, the two QSPR models were validated using the coefficient of determination (R2) of 0.62 for both models with the leave-one-out cross-validation correlation coefficient (Q2LOO) of 0.55 and 0.57, respectively. Furthermore, applicability domain analysis was conducted in order to identify the related compounds via the extrapolation of the model.

Natural Frequencies Identification by FEM Applied to a 2-DOF Planar Robot and Its Validation Using MUSIC Algorithm.

In this paper, the natural frequencies (NFs) identification by finite element method (FEM) is applied to a two degrees-of-freedom (2-DOF) planar robot, and its validation through a novel experimental methodology, the Multiple Signal Classification (MUSIC) algorithm, is presented. The experimental platforms are two different 2-DOF planar robots with different materials for the links and different types of actuators. The FEM is carried out using ANSYS™ software for the experiments, with vibration signal analysis by MUSIC algorithm. The advantages of the MUSIC algorithm against the commonly used fast Fourier transform (FFT) method are also presented for a synthetic signal contaminated by three different noise levels. The analytical and experimental results show that the proposed methodology identifies the NFs of a high-resolution robot even when they are very closed and when the signal is embedded in high-level noise. Furthermore, the results show that the proposed methodology can obtain a high-frequency resolution with a short sample data set. Identifying the NFs of robots is useful for avoiding such frequencies in the path planning and in the selection of controller gains that establish the bandwidth.

Smart Sensor Based on Biofeedback to Measure Child Relaxation in Out-of-Home Care.

Children from out-of-home care are a vulnerable population that faces high stress and anxiety levels due to stressful experiences, such as being abused, being raped, and violence. This problem could have negative effects on their bio-psycho-social well-being if they are not provided with comprehensive psychological treatment. Numerous methods have been developed to help them relax, but there are no current approaches for assessing the relaxation level they reach. Based on this, a novel smart sensor that can evaluate the level of relaxation a child experiences is developed in this paper. It evaluates changes in thermal biomarkers (forehead, right and left cheek, chin, and maxillary) and heart rate (HR). Then, through a k-nearest neighbors (K-NN) intelligent classifier, four possible levels of relaxation can be obtained: no-relax, low-relax, relax, and very-relax. Additionally, an application (called i-CARE) for anxiety management, which is based on biofeedback diaphragmatic breathing, guided imagery, and video games, is evaluated. After testing the developed smart sensor, an 89.7% accuracy is obtained. The smart sensor used provides a reliable measurement of relaxation levels and the i-CARE application is effective for anxiety management, both of which are focused on children exposed to out-of-home care conditions.