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INTRODUCTION/AIMS: Cough impairment is common in individuals with neuromuscular disorders and is associated with respiratory infections and shorter survival. Cough strength is assessed by measuring cough peak flow (CPF) using a flow meter, but this method requires a complex device setup and trained staff. The aim of the study is to evaluate the reliability of a smartphone app to estimate CPF based on cough sounds in a cohort of individuals with neuromuscular disorders. METHODS: Individuals with neuromuscular disorders underwent CPF measurement with a flow meter and a smartphone app. A CPF <270 L/min was considered abnormal. RESULTS: Of the 50 patients studied, 26 had amyotrophic lateral sclerosis (52%), 15 had hereditary myopathies (30%), and 9 had myasthenia gravis (18%). The intraclass correlation coefficient (ICC) between the CPF measured with a flow meter and CPF estimated with cough sounds was 0.774 (p < .001) even if the patients had orofacial weakness (ICC = 0.806, p < .001). The smartphone app had 94.4% sensitivity and 100% specificity to detect patients with CPF of less than 270 L/min. DISCUSSION: Our findings suggest that sounds measured with a smartphone app provide a reliable estimate of CPF in patients with neuromuscular disorders, even in the presence of with orofacial weakness. This may be a convenient way to monitor respiratory involvement in patients with neuromuscular disorders, but larger studies of more diverse patient cohorts are needed.
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Doenças do Sistema Nervoso , Doenças Neuromusculares , Humanos , Reprodutibilidade dos Testes , Doenças Neuromusculares/complicações , Pico do Fluxo Expiratório , TosseRESUMO
BACKGROUND: People who were previously hospitalised with stroke may have difficulty operating a motor vehicle, and their driving aptitude needs to be evaluated to prevent traffic accidents in today's car-based society. Although the association between motor-cognitive functions and driving aptitude has been extensively studied, motor-cognitive functions required for driving have not been elucidated. METHODS: In this paper, we propose a machine-learning algorithm that introduces sparse regularization to automatically select driving aptitude-related indices from 65 input indices obtained from 10 tests of motor-cognitive function conducted on 55 participants with stroke. Indices related to driving aptitude and their required tests can be identified based on the output probability of the presence or absence of driving aptitude to provide evidence for identifying subjects who must undergo the on-road driving test. We also analyzed the importance of the indices of motor-cognitive function tests in evaluating driving aptitude to further clarify the relationship between motor-cognitive function and driving aptitude. RESULTS: The experimental results showed that the proposed method achieved predictive evaluation of the presence or absence of driving aptitude with high accuracy (area under curve 0.946) and identified a group of indices of motor-cognitive function tests that are strongly related to driving aptitude. CONCLUSIONS: The proposed method is able to effectively and accurately unravel driving-related motor-cognitive functions from a panoply of test results, allowing for autonomous evaluation of driving aptitude in post-stroke individuals. This has the potential to reduce the number of screening tests required and the corresponding clinical workload, further improving personal and public safety and the quality of life of individuals with stroke.
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Condução de Veículo , Acidente Vascular Cerebral , Humanos , Condução de Veículo/psicologia , Qualidade de Vida , Acidentes de Trânsito/prevenção & controle , Cognição , Aprendizado de MáquinaRESUMO
Considering quality of life (QOL) after stroke, car driving is one of the most important abilities for returning to the community. In this study, directed attention and sustained attention, which are thought to be crucial for driving, were examined. Identification of specific brain structure abnormalities associated with post-stroke cognitive dysfunction related to driving ability would help in determining fitness for car driving after stroke. Magnetic resonance imaging was performed in 57 post-stroke patients (51 men; mean age, 63 ± 11 years) who were assessed for attention deficit using a standardized test (the Clinical Assessment for Attention, CAT), which includes a Continuous Performance Test (CPT)-simple version (CPT-SRT), the Behavioral Inattention Test (BIT), and a driving simulator (handle task for dividing attention, and simple and selective reaction times for sustained attention). A statistical non-parametric map (SnPM) that displayed the association between lesion location and cognitive function for car driving was created. From the SnPM analysis, the overlay plots were localized to the right hemisphere during handling the hit task for bilateral sides (left hemisphere damage related to right-side neglect and right hemisphere damage related to left-side neglect) and during simple and selective reaction times (false recognition was related to damage of both hemispheres). A stepwise multiple linear regression analysis confirmed the importance of both hemispheres, especially the right hemisphere, for cognitive function and car driving ability. The present study demonstrated that the right hemisphere has a crucial role for maintaining directed attention and sustained attention, which maintain car driving ability, improving QOL for stroke survivors.
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Condução de Veículo , Cognição/fisiologia , Disfunção Cognitiva/diagnóstico por imagem , Lateralidade Funcional/fisiologia , Acidente Vascular Cerebral/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Condução de Veículo/psicologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/psicologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/tendências , Masculino , Pessoa de Meia-Idade , Tempo de Reação/fisiologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/psicologiaRESUMO
Cough peak flow (CPF) is a measurement for evaluating the risk of cough dysfunction and can be measured using various devices, such as spirometers. However, complex device setup and the face mask required to be firmly attached to the mouth impose burdens on both patients and their caregivers. Therefore, this study develops a novel cough strength evaluation method using cough sounds. This paper presents an exponential model to estimate CPF from the cough peak sound pressure level (CPSL). We investigated the relationship between cough sounds and cough flows and the effects of a measurement condition of cough sound, microphone type and participant's height and gender on CPF estimation accuracy. The results confirmed that the proposed model estimated CPF with a high accuracy. The absolute error between CPFs and estimated CPFs were significantly lower when the microphone distance from the participant's mouth was within 30 cm than when the distance exceeded 30 cm. Analysis of the model parameters showed that the estimation accuracy was not affected by participant's height or gender. These results indicate that the proposed model has the potential to improve the feasibility of measuring and assessing CPF.
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Tosse/fisiopatologia , Pico do Fluxo Expiratório , Som , Adulto , Feminino , Humanos , Masculino , Sensibilidade e Especificidade , Espirometria , Adulto JovemRESUMO
Although cough peak flow (CPF) is an important measurement for evaluating the risk of cough dysfunction, some patients cannot use conventional measurement instruments, such as spirometers, because of the configurational burden of the instruments. Therefore, we previously developed a cough strength estimation method using cough sounds based on a simple acoustic and aerodynamic model. However, the previous model did not consider age or have a user interface for practical application. This study clarifies the cough strength prediction accuracy using an improved model in young and elderly participants. Additionally, a user interface for mobile devices was developed to record cough sounds and estimate cough strength using the proposed method. We then performed experiments on 33 young participants (21.3 ± 0.4 years) and 25 elderly participants (80.4 ± 6.1 years) to test the effect of age on the CPF estimation accuracy. The percentage error between the measured and estimated CPFs was approximately 6.19%. In addition, among the elderly participants, the current model improved the estimation accuracy of the previous model by a percentage error of approximately 6.5% (p < 0.001). Furthermore, Bland-Altman analysis demonstrated no systematic error between the measured and estimated CPFs. These results suggest that the developed device can be applied for daily CPF measurements in clinical practice.
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Tosse/diagnóstico , Som , Espirometria/métodos , Acústica , Adulto , Idoso , Idoso de 80 Anos ou mais , Tosse/fisiopatologia , Feminino , Humanos , MasculinoRESUMO
During cardiopulmonary bypass (CPB), blood viscosity conspicuously increases and decreases due to changes in hematocrit and blood temperature. Nevertheless, blood viscosity is typically not evaluated, because there is no technology that can provide simple, continuous, noncontact monitoring. We modeled the pressure-flow characteristics of an oxygenator in a previous study, and in that study we quantified the influence of viscosity on oxygenator function. The pressure-flow monitoring information in the oxygenator is derived from our model and enables the estimation of viscosity. The viscosity estimation method was proposed and investigated in an in vitro experiment. Three samples of whole bovine blood with different hematocrit levels (21.8, 31.0, and 39.8%) were prepared and perfused into the oxygenator. As the temperature changed from 37°C to 27°C, the mean inlet pressure (Pin ) and outlet pressure (Pout ) of the oxygenator and the flow (Q) and viscosity of the blood were measured. The estimated viscosity was calculated from the pressure gradient (ΔP = Pin - Pout ) and Q and was compared to the measured blood viscosity. A strong correlation was found between the two methods for all samples. Bland-Altman analysis revealed a mean bias of -0.0263 mPa.s, a standard deviation of 0.071 mPa.s, limits of agreement of -0.114-0.166 mPa.s, and a percent error of 5%. Therefore, this method is considered compatible with the torsional oscillation viscometer that has plus or minus 5% measurement accuracy. Our study offers the possibility of continuously estimating blood viscosity during CPB.
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Pressão Sanguínea , Viscosidade Sanguínea , Ponte Cardiopulmonar/instrumentação , Modelos Cardiovasculares , Oxigenadores , Animais , Velocidade do Fluxo Sanguíneo , Bovinos , Hematócrito , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Temperatura , Fatores de TempoRESUMO
Generally, odor qualities are evaluated via sensory tests in which predefined criteria are assessed by panelists and stochastically analyzed to reduce human inconsistencies. Because this method requires multiple, well-trained human subjects, a more convenient approach is required to enable predictions of odor qualities. In this article, we propose an approach involving linking internal states of the olfactory system with perceptual characteristics. In the study, the glomerular responses of rats were taken to represent internal olfactory system states. Similarities between the glomerular responses of rats were quantified by correlations between glomerular activity patterns, overlap rate of strongly activated part across glomerular activity patterns, and the similarity between histograms of the strength of activity. These indices were then compared with perceptual similarities measured from human subjects in sensory tests. The results of experiments involving 22 odorants showed medium strength correlations between each index and perceptual similarity. In addition, when the 3 indices were combined using their Euclidean distance, we observed middle to high correlations (r = 0.65-0.79) to human perceptual similarity. We also report the results of our use of a machine learning technique to classify the odorants into a similar and dissimilar category. Although the correct rate of classification varied from 33.3% to 92.9%, these results support the feasibility of linking the glomerular responses of rats to human perception.
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Bulbo Olfatório/fisiologia , Percepção Olfatória/fisiologia , Animais , Inteligência Artificial , Cibernética , Desoxiglucose/metabolismo , Humanos , Modelos Neurológicos , Odorantes , Ratos , Olfato/fisiologia , Especificidade da EspécieRESUMO
The study aimed to investigate the effect of red blood cell (RBC) morphology on oxygenator perfusion, focusing on stages of echinocytosis and their correlation with blood viscosity. A test circuit with an oxygenator and human RBC mixtures was used to induce changes in RBC shape by increasing sodium salicylate concentrations (0, 10, 20, 30, 60, and 120 mmol/L), while hematocrit, blood temperature, and anticoagulation were maintained. Blood viscosity was measured using a continuous blood viscosity monitoring system based on pressure-flow characteristics. Under a scanning electron microscope, the percentages of discocytes, echinocytes I-III, spheroechinocytes, and spherocytes were determined from approximately 400 cells per RBC sample. Early echinocytes, mainly discocytes and echinocytes I and II in the range of 0-30 mmol/L were predominant, resulting in a gradual increase in blood viscosity from 1.78 ± 0.12 to 1.94 ± 0.12 mPa s. At 60 mmol/L spherocytes emerged, and at 120 mmol/L, spheroidal RBCs constituted 50% of the population, and blood viscosity sharply rose to 2.50 ± 0.15 mPa s, indicating a 40% overall increase. In conclusion, the presence of spherocytes significantly increases blood viscosity, which may affect oxygenator perfusion.
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Anticipation of pain engenders anxiety and fear, potentially shaping pain perception and governing bodily responses such as peripheral vasomotion through the sympathetic nervous system (SNS). Sympathetic innervation of vascular tone during pain perception has been quantified using a peripheral arterial stiffness index; however, its innervation role during pain anticipation remains unclear. This paper reports on a neuroimaging-based study designed to investigate the responsivity and attribution of the index at different levels of anticipatory anxiety and pain perception. The index was measured in a functional magnetic resonance imaging experiment that randomly combined three visual anticipation cues and painful stimuli of two intensities. The peripheral and cerebral responses to pain anticipation and perception were quantified to corroborate bodily responsivity, and their temporal correlation was also assessed to identify the response attribution of the index. Contrasting with the high responsivity across levels of pain sensation, a low responsivity of the index across levels of anticipatory anxiety revealed its specificity across pain experiences. Discrepancies between the effects of perception and anticipation were validated across regions and levels of brain activity, providing a brain basis for peripheral response specificity. The index was also characterized by a 1-s lag in both anticipation and perception of pain, implying top-down innervation of the periphery. Our findings suggest that the SNS responds to pain in an emotion-specific and sensation-unbiased manner, thus enabling an early assessment of individual pain perception using this index. This study integrates peripheral and cerebral hemodynamic responses toward a comprehensive understanding of bodily responses to pain.
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Encéfalo , Dor , Humanos , Encéfalo/diagnóstico por imagem , Percepção da Dor/fisiologia , Medo/fisiologia , Neuroimagem , Imageamento por Ressonância Magnética , Antecipação Psicológica/fisiologiaRESUMO
GOAL: Microbubbles (MBs) are known to occur within the circuits of cardiopulmonary bypass (CPB) systems, and higher-order dysfunction after cardiac surgery may be caused by MBs as well as atheroma dispersal associated with cannula insertion. As complete MB elimination is not possible, monitoring MB count rates is critical. We propose an online detection system with a neural network-based model to estimate MB count rate using five parameters: suction flow rate, venous reservoir level, perfusion flow rate, hematocrit level, and blood temperature. METHODS: Perfusion experiments were performed using an actual CPB circuit, and MB count rates were measured using the five varying parameters. RESULTS: Bland-Altman analysis indicated a high estimation accuracy (R2 > 0.95, p < 0.001) with no significant systematic error. In clinical practice, although the inclusion of clinical procedures slightly decreased the estimation accuracy, a high coefficient of determination for 30 clinical cases (R2 = 0.8576) was achieved between measured and estimated MB count rates. CONCLUSIONS: Our results highlight the potential of this system to improve patient outcomes and reduce MB-associated complication risk.
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We investigated a newly developed digitized Trail Making Test using an iPad (iTMT) as a brief cognitive function screening test. We found that the iTMT part-A (iTMT-A) can estimate generalized cognitive function in rehabilitation inpatients examined using the Mini-Mental State Examination (MMSE). Forty-two hospitalized participants undergoing rehabilitation (rehab participants), 30 of whom had cerebral infarction/hemorrhage (stroke participants), performed the iTMT five times (first three times: iTMT-A; fourth: paper version of TMT-A; fifth: the inverse version of iTMT-A) and the MMSE once. Each iTMT-A trial's completion time was divided into the move and dwell times. A linear mixed model following post-hoc tests revealed that the completion time of the third and fourth iTMT-A was faster compared to that of the first iTMT-A, suggesting the presence of a learning effect. In the partial least squares (PLS) regression analysis, the coefficient of determination for estimating the MMSE score was increased by using the dwell and move times extracted from the repeated iTMT-A and the availability of TMT-B, even for subjects with low MMSE scores. These findings indicate that the dwell time of iTMT-A may be important for estimating cognitive function. The iTMT-A extracts significant factors temporally and spatially, and by incorporating the learning effect of repeated trials, it may be possible to screen cognitive and physical functions for rehabilitation patients.
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Dynamic visual acuity (DVA) is crucial for the perception of moving objects. While traditional DVA assessment tools predominantly focus on horizontal movements, the evaluation of vertical DVA remains unstandardized. Consequently, the disparities between vertical and horizontal DVAs are yet to be thoroughly investigated. Therefore, we designed a system capable of conducting multidirectional DVA tests and eye movement measurements. During the experiments, the participants identified the gap direction of the Landolt-C ring moving either horizontally or vertically. The speed of movement decelerated from its maximum as a high-speed infrared camera captured the pupil movements of the left eye at 500 fps. We conducted tests on 15 healthy university students (aged [Formula: see text] years) and measured vertical and horizontal DVAs five times each. DVA was deduced from the Landolt-C ring speed with accurate gap direction responses, and eye movement was assessed based on the total gaze movement distance. The results revealed superior DVA and eye movement in the horizontal direction compared with the vertical direction ([Formula: see text]). This highlights the anisotropic characteristics of DVA and eye movement. The proposed system has the potential for multidirectional dynamic vision evaluation and training in clinical scenarios.
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Movimentos Oculares , Movimento , Humanos , Idoso , Acuidade Visual , Testes Visuais , Medições dos Movimentos OcularesRESUMO
Introduction: The peripheral arterial stiffness index has been proposed and validated as a noninvasive measure quantifying stimulus intensity based on amplitude changes induced by sympathetic innervation of vascular tone. However, its temporal response characteristics remain unclear, thus hindering continuous and accurate monitoring of the dynamic process of sympathetic activation. This paper presents a study aimed at modeling the transient response of the index across sensory stimuli to characterize the corresponding peripheral sympathetic activation. Methods: The index was measured using a continuous arterial pressure monitor and a pulse oximeter during experiments with local pain and local cooling stimuli designed to elicit different patterns of sympathetic activation. The corresponding response of the index was modeled to clarify its transient response characteristics across stimuli. Results: The constructed transfer function accurately depicted the transient response of the index to local pain and local cooling stimuli (Fit percentage: 78.4% ± 11.00% and 79.92% ± 8.79%). Differences in dead time (1.17 ± 0.67 and 0.99 ± 0.56 s, p = 0.082), peak time (2.89 ± 0.81 and 2.64 ± 0.68 s, p = 0.006), and rise time (1.81 ± 0.50 and 1.65 ± 0.48 s, p = 0.020) revealed different response patterns of the index across stimuli. The index also accurately characterized similar vasomotor velocities at different normalized peak amplitudes (0.19 ± 0.16 and 0.16 ± 0.19 a.u., p = 0.007). Discussion: Our findings flesh out the characterization of peripheral arterial stiffness index responses to different sensory stimuli and demonstrate its validity in characterizing peripheral sympathetic activation. This study valorizes a noninvasive method to characterize peripheral sympathetic activation, with the potential to use this index to continuously and accurately track sympathetic activators.
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Cardiopulmonary bypass (CPB) is an indispensable technique in cardiac surgery, providing the ability to temporarily replace cardiopulmonary function and create a bloodless surgical field. Traditionally, the operation of CPB systems has depended on the expertise and experience of skilled perfusionists. In particular, simultaneously controlling the arterial and venous occluders is difficult because the blood flow rate and reservoir level both change, and failure may put the patient's life at risk. This study proposes an automatic control system with a two-degree-of-freedom model matching controller nested in an I-PD feedback controller to simultaneously regulate the blood flow rate and reservoir level. CPB operations were performed using glycerin and bovine blood as perfusate to simulate flow-up and flow-down phases. The results confirmed that the arterial blood flow rate followed the manually adjusted target venous blood flow rate, with an error of less than 5.32%, and the reservoir level was maintained, with an error of less than 3.44% from the target reservoir level. Then, we assessed the robustness of the control system against disturbances caused by venting/suction of blood. The resulting flow rate error was 5.95%, and the reservoir level error 2.02%. The accuracy of the proposed system is clinically satisfactory and within the allowable error range of 10% or less, meeting the standards set for perfusionists. Moreover, because of the system's simple configuration, consisting of a camera and notebook PC, the system can easily be integrated with general CPB equipment. This practical design enables seamless adoption in clinical settings. With these advancements, the proposed system represents a significant step towards the automation of CPB.
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Procedimentos Cirúrgicos Cardíacos , Ponte Cardiopulmonar , Humanos , Animais , Bovinos , Cateteres de Demora , Máquina Coração-PulmãoRESUMO
This study presents a novel approach for estimating vital capacity using cough sounds and proposes a neural network-based model that utilizes the reference vital capacity computed using the lambda-mu-sigma method, a conventional approach, and the cough peak flow computed based on the cough sound pressure level as inputs. Additionally, a simplified cough sound input model is developed, with the cough sound pressure level used directly as the input instead of the computed cough peak flow. A total of 56 samples of cough sounds and vital capacities were collected from 31 young and 25 elderly participants. Model performance was evaluated using squared errors, and statistical tests including the Friedman and Holm tests were conducted to compare the squared errors of the different models. The proposed model achieved a significantly smaller squared error (0.052 L2, p < 0.001) than the other models. Subsequently, the proposed model and the cough sound-based estimation model were used to detect whether a participant's vital capacity was lower than the typical lower limit. The proposed model demonstrated a significantly higher area under the receiver operating characteristic curve (0.831, p < 0.001) than the other models. These results highlight the effectiveness of the proposed model for screening decreased vital capacity.
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Tosse , Som , Humanos , Idoso , Tosse/diagnóstico , Redes Neurais de Computação , Pico do Fluxo Expiratório , Capacidade VitalRESUMO
A neural oscillator with a double-chain structure is one of the central pattern generator models used to simulate and understand rhythmic movements in living organisms. However, it is difficult to reproduce desired rhythmic signals by tuning an enormous number of parameters of neural oscillators. In this study, we propose an automatic tuning method consisting of two parts. The first involves tuning rules for both the time constants and the amplitude of the oscillatory outputs based on theoretical analyses of the relationship between parameters and outputs of the neural oscillators. The second involves an evolutionary tuning method with a two-step genetic algorithm (GA), consisting of a global GA and a local GA, for tuning parameters such as neural connection weights that have no exact tuning rule. Using numerical experiments, we confirmed that the proposed tuning method could successfully tune all parameters and generate sinusoidal waves. The tuning performance of the proposed method was less affected by factors such as the number of excitatory oscillators or the desired outputs. Furthermore, the proposed method was applied to the parameter-tuning problem of some types of artificial and biological wave reproduction and yielded optimal parameter values that generated complex rhythmic signals in Caenorhabditis elegans without trial and error.
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Algoritmos , Relógios Biológicos/fisiologia , Modelos Neurológicos , Animais , Caenorhabditis elegansRESUMO
The zebrafish is widely used as a model in biological studies. In particular, the heart rate and cortisol levels of zebrafish are commonly measured to elucidate the pharmacological effects of chemical substances. Meanwhile, although ventilation is also an important physiological index reflecting emotion-like states, few studies have evaluated the effects of chemicals on ventilation in adult zebrafish. In this study, we assessed whether it is possible to evaluate the pharmacological effects elicited by caffeine in adult zebrafish under free-swimming conditions. We measured the ventilation in adult zebrafish exposed to multiple concentrations of caffeine under restraint and free-swimming conditions and evaluated the pharmacological effects of caffeine using linear mixed model analysis. In addition, results of electrocardiogram analysis and swimming speeds were compared with those in previous reports to ensure that an appropriate dose of caffeine was administered. Under restraint conditions, caffeine significantly decreased heart rate and increased ventilation in a concentration-dependent manner. Under free-swimming conditions, the ventilation rate significantly increased with increasing caffeine concentration. These results indicate that the pharmacological effects elicited by chemicals on ventilation can be evaluated in free-swimming zebrafish.
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Cafeína , Peixe-Zebra , Animais , Peixe-Zebra/fisiologia , Cafeína/farmacologia , Natação , Hidrocortisona/farmacologia , Respiração , Comportamento AnimalRESUMO
The cardiopulmonary bypass system used in cardiac surgery can generate microbubbles (MBs) that may cause complications, such as neurocognitive dysfunction, when delivered into the blood vessel. Estimating the number of MBs generated, thus, is necessary to enable the surgeons to deal with it. To this end, we previously proposed a neural network-based model for estimating the number of MBs from four factors measurable from the cardiopulmonary bypass system: suction flow rate, venous reservoir level, blood viscosity, and perfusion flow rate. However, the model has not been adapted to the data collected from actual surgery cases. In this study, the accuracy of MBs estimated by the proposed model was examined in four clinical cases. The results showed that the coefficient of determination between estimated MBs and the measured MBs throughout the surgeries was R2=0.558 (p<0.001). We found that the surgical treatments, such as administration of drugs, fluids and blood transfusions, increased the number of measured MBs. The coefficient of determination increased to R2= 0.8762 (p<0.001) by excluding the duration of these treatments. This result indicates that the model can estimate the number of MBs with high accuracy under the clinical environment.
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Disfunção Cognitiva , Microbolhas , Viscosidade Sanguínea , Ponte Cardiopulmonar , Humanos , Redes Neurais de ComputaçãoRESUMO
Early intervention is now considered the core treatment strategy for autism spectrum disorders (ASD). Thus, it is of significant clinical importance to establish a screening tool for the early detection of ASD in infants. To achieve this goal, in a longitudinal design, we analyzed spontaneous bodily movements of 4-month-old infants from general population and assessed their ASD-like behaviors at 18 months of age. A total of 26 movement features were calculated from video-recorded bodily movements of infants at 4 months of age. Their risk of ASD was assessed at 18 months of age with the Modified Checklist for Autism in Toddlerhood, a widely used screening questionnaire. Infants at high risk for ASD at 18 months of age exhibited less rhythmic and weaker bodily movement patterns at 4 months of age than low-risk infants. When the observed bodily movement patterns were submitted to a machine learning-based analysis, linear and non-linear classifiers successfully predicted ASD-like behavior at 18 months of age based on the bodily movement patterns at 4 months of age, at the level acceptable for practical use. This study analyzed the relationship between spontaneous bodily movements at 4 months of age and the ASD risk at 18 months of age. Experimental results suggested the utility of the proposed method for the early screening of infants at risk for ASD. We revealed that the signs of ASD risk could be detected as early as 4 months after birth, by focusing on the infant's spontaneous bodily movements.
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Transtorno do Espectro Autista , Transtorno Autístico , Lactente , Humanos , Transtorno Autístico/diagnóstico , Transtorno do Espectro Autista/diagnóstico , Movimento , Diagnóstico Precoce , RiscoRESUMO
This paper proposes a neural network model for prediction of olfactory glomerular activity aimed at future application to the evaluation of odor qualities. The model's input is the structure of an odorant molecule expressed as a labeled graph, and it employs the graph kernel method to quantify structural similarities between odorants and the function of olfactory receptor neurons. An artificial neural network then converts odorant molecules into glomerular activity expressed in Gaussian mixture functions. The authors also propose a learning algorithm that allows adjustment of the parameters included in the model using a learning data set composed of pairs of odorants and measured glomerular activity patterns. We observed that the defined similarity between odorant structure has correlation of 0.3-0.9 with that of glomerular activity. Glomerular activity prediction simulation showed a certain level of prediction ability where the predicted glomerular activity patterns also correlate the measured ones with middle to high correlation in average for data sets containing 363 odorants.