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1.
J Sports Sci ; 38(5): 503-510, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31865845

RESUMO

Accelerometer cut points are an important consideration for distinguishing the intensity of activity into categories such as moderate and vigorous. It is well-established in the literature that these cut points depend on a variety of factors, including age group, device, and wear location. The Actigraph GT9X is a newer model accelerometer that is used for physical activity research, but existing cut points for this device are limited since it is a newer device. Furthermore, there is not existing data on cut points for the GT9X at the ankle or foot locations, which offers some potential benefit for activities that do not involve arm and/or core motion. A total of N = 44 adults completed a four-stage treadmill protocol while wearing Actigraph GT9X sensors at four different locations: foot, ankle, wrist, and hip. Metabolic Equivalent of Task (MET) levels assessed by indirect calorimetry along with Receiver Operating Characteristic (ROC) curves were used to establish cut points for moderate and vigorous intensity for each wear location of the GT9X. Area under the ROC curves indicated high discrimination accuracy for each case.


Assuntos
Actigrafia/instrumentação , Actigrafia/estatística & dados numéricos , Exercício/fisiologia , Monitores de Aptidão Física/estatística & dados numéricos , Acelerometria/instrumentação , Acelerometria/estatística & dados numéricos , Adulto , Tornozelo , Calorimetria Indireta , Teste de Esforço , Feminino , , Quadril , Humanos , Masculino , Curva ROC , Valores de Referência , Punho
2.
Expert Rev Med Devices ; 16(12): 1041-1052, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31774330

RESUMO

Introduction: Sleep assessment devices are essential for the detection, diagnosis, and monitoring of sleep disorders. This paper provides a state-of-the-art review and comparison of sleep assessment devices and a market analysis.Areas covered: Hardware devices are classified into contact and contactless devices. For each group, the underlying technologies are presented, paying special attention to their limitations. A systematic literature review has been carried out by comparing the most important validation studies of sleep tracking devices in terms of sensitivity and specificity. A market analysis has also been carried out in order to list the most used, best-selling, and most highly-valued devices. Software apps have also been compared with regards to the market.Expert opinion: Thanks to technological advances, the reliability and accuracy of sensors has been significantly increased in recent years. According to validation studies, some actigraphs present a sensibility higher than 90%. However, the market analysis reveals that many hardware devices have not been validated, and especially software devices should be studied before their clinical use.


Assuntos
Marketing , Polissonografia/economia , Polissonografia/instrumentação , Sono/fisiologia , Actigrafia/instrumentação , Humanos , Reprodutibilidade dos Testes , Software
3.
J Sports Sci ; 37(23): 2751-2758, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31506039

RESUMO

This study used the intensity gradient (IG) and average acceleration metrics to describe children's activity profiles and explore associations with body mass index (BMI) z-score. Two hundred and forty-six children (n = 138 girls) aged 9.6 ± 1.4 years wore a wrist-mounted ActiGraph wGT3X-BT accelerometer for 7 days on their non-dominant wrist. Physical activity (PA) metrics captured included: the IG which describes the intensity distribution of accelerations across the 24 h monitoring period; average acceleration which provides a measure of the volume of activity; total moderate-to-vigorous PA (MVPA) and inactive time. Acceleration was averaged over 5s epochs. Finally, BMI z-score was calculated for each participant. Average acceleration was negatively associated with BMI z-score (p < 0.05) independent of age and gender but not IG. The IG was negatively associated with BMI z-score independent of potential correlates and average acceleration. Total MVPA was not associated with BMI-z score. The IG and average acceleration metrics may be used to explore the independent or cumulative effects of the volume and intensity distribution of activity upon measures of health and well-being in children to inform specific activity recommendations.


Assuntos
Índice de Massa Corporal , Exercício/fisiologia , Aceleração , Actigrafia/instrumentação , Criança , Estudos Transversais , Feminino , Monitores de Aptidão Física , Humanos , Masculino , Análise de Regressão , Corrida/fisiologia , Comportamento Sedentário , Velocidade de Caminhada/fisiologia
4.
J Sports Sci ; 37(23): 2691-2701, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31526108

RESUMO

This study investigated effects of total sleep deprivation on self-paced endurance performance, and heart rate (HR) indices of athletes' "readiness to perform". Endurance athletes (n = 13) completed a crossover experiment comprising a normal sleep (NS) and sleep deprivation (SD) condition. Each required completion of an endurance time-trial (TT) on consecutive days (D1, D2) separated by normal sleep or total sleep deprivation. Finishing time, perceived exertion (RPE), mood, psychomotor vigilance (PVT), and HR responses were assessed. Time on D2 of SD was 10% slower than D2 of NS (64 ± 7 vs 59 ± 4 min, P < 0.01), and 11% slower than D1 of SD (58 ± 5 min, P < 0.01). Subjective to objective (RPE:mean HR) intensity ratio was higher on D2 of SD compared with D2 of NS and D1 of SD (P < 0.01). Mood disturbance and PVT mean response time increased on D2 of SD compared with D2 of NS and D1 of SD. Anaerobic threshold and change in TT time were correlated (R = -0.73, P < 0.01). Sleep helps to optimise endurance performance. Subjective to objective intensity ratios appear sensitive to effects of sleep on athletes' readiness. Research examining more subtle sleep manipulation is required.


Assuntos
Ciclismo/fisiologia , Frequência Cardíaca/fisiologia , Resistência Física/fisiologia , Privação do Sono/fisiopatologia , Actigrafia/instrumentação , Adulto , Afeto/fisiologia , Ciclismo/psicologia , Estudos Cross-Over , Teste de Esforço , Humanos , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Tempo de Reação/fisiologia , Dispositivos Eletrônicos Vestíveis
5.
Eur Arch Otorhinolaryngol ; 276(11): 3057-3065, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31444561

RESUMO

BACKGROUND: Classical posturography techniques have been recently enhanced by the use of different motion tracking devices, but for technical reasons they are not used to track directly the body spatial position of a subject. OBJECTIVE: To describe and clinically evaluate a wireless inertial measurement unit-based mobile system to track body position changes. METHODS: The developed system used a calculus transformation method using the acceleration data corrected by Kalman and Butterworth filters to output position data. A prospective non-randomized clinical study involving 15 healthy subjects was performed to evaluate the agreement between the confidence ellipse areas synchronously measured by the new developed system and a classical posturography system while performing a modified clinical test of sensory interaction in balance. RESULTS: The overall intra-class correlation index was 0.93 (CI 0.89, 0.96). Grouped by conditions, under conditions 1-4, Pearson's correlation was 0.604, 0.78, 0.882, and 0.81, respectively. CONCLUSION: The developed wireless inertial measurement unit-based posturography system was valid for tracking the sway variances in normal subjects under habitual clinical testing conditions. Further studies are needed to validate this system on patients and also under other posture conditions.


Assuntos
Actigrafia , Movimento , Equilíbrio Postural , Postura , Aceleração , Acelerometria/instrumentação , Acelerometria/métodos , Actigrafia/instrumentação , Actigrafia/métodos , Adulto , Feminino , Humanos , Masculino , Teste de Materiais , Estudos Prospectivos , Tecnologia sem Fio
6.
Artigo em Inglês | MEDLINE | ID: mdl-31466248

RESUMO

Different models of accelerometer have the potential to provide a different estimate of the same physical activity or sedentary behavior. Our study compared the outputs of the Active Style Pro (ASP) and ActiGraph (AG) devices in assessing predicted metabolic equivalents (METs) for specific activities under laboratory conditions. Thirty healthy young adults wore two hip accelerometers (ASP and AG), simultaneously while performing twenty-two activities (eight sedentary, eight household, and six ambulatory activities) in a controlled laboratory setting. For the AG, predicted METs for each activity was calculated using four equations based on vertical-axis and vector magnitude data. Separate paired t-tests and Bland-Altman analysis examined the difference and agreement in METs between AG using four commonly used equations and ASP measurements for each activity. AG devices using different equations calculated significantly different outcomes for most activities compared with ASP devices. The smallest differences in predicted METs estimates between ASP and AG were observed for ambulatory activities. Ambulatory activities demonstrated the best agreement between ASP and AG regardless of which AG equation was used. Our findings can be used to assist researchers in their selection of accelerometer and output estimation equations for measuring physical activity and sedentary behavior in adults.


Assuntos
Acelerometria/instrumentação , Actigrafia/instrumentação , Exercício , Comportamento Sedentário , Adulto , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Adulto Jovem
7.
Artigo em Inglês | MEDLINE | ID: mdl-31450754

RESUMO

Various accelerometers have been used in research measuring physical activity (PA) and sedentary behavior (SB). This study compared two triaxial accelerometers-Active style Pro (ASP) and ActiGraph (AG)-in measuring PA and SB during work and nonwork days in free-living conditions. A total of 50 working participants simultaneously wore these two accelerometers on one work day and one nonwork day. The difference and agreement between the ASP and AG were analyzed using paired t-tests, Bland-Altman plots, and intraclass coefficients, respectively. Correction factors were provided by linear regression analysis. The agreement in intraclass coefficients was high among all PA intensities between ASP and AG. SB in the AG vertical axis was approximately 103 min greater than ASP. Regarding moderate-to-vigorous-intensity PA (MVPA), ASP had the greatest amount, followed by AG. There were significant differences in all variables among these devices across all day classifications, except for SB between ASP and AG vector magnitude. The correction factors decreased the differences of SB and MVPA. PA time differed significantly between ASP and AG. However, SB and MVPA differences between these two devices can be decreased using correction factors, which are useful methods for public health researchers.


Assuntos
Actigrafia/estatística & dados numéricos , Exercício , Comportamento Sedentário , Actigrafia/instrumentação , Adulto , Feminino , Inquéritos Epidemiológicos , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
8.
Int J Chron Obstruct Pulmon Dis ; 14: 1317-1322, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354259

RESUMO

Background: Physical activity is an important predictor for survival in patients with COPD. Wearable technology, such as pedometer or accelerometer, may offer an opportunity to quantify physical activity and evaluate related health benefits in these patients. Objectives: To assess the performance of wearable technology in monitoring and improving physical activity in COPD patients from published studies. Methods: Literature search of Medline, Cochrane, Dare, Embase and PubMed databases was made to find relevant articles that used wearable technology to monitor physical activity in COPD patients. Results: We identified 13 studies that used wearable technology, a pedometer or an accelerator, to monitor physical activity in COPD patients. Of these, six studies were randomized controlled trials (RCTs) which used the monitors as part of the intervention. Two studies reported the same outcomes and comparable units. They had measured the difference that the intervention makes on the number of steps taken daily by the patients. The results were highly heterogeneous with I2=92%. The random-effects model gave an effect outcome on the number of steps taken daily of 1,821.01 [-282.71; 3,924.74] in favor of the wearable technology. Four of the 13 studies have reported technical issues with the use of the wearable technology, including high signal-to-noise ratio, memory storage problems and inaccuracy of counts. While other studies did not mention any technical issues, it is not clear whether these did not experience them or chose not to report them. Conclusions: Our literature search has shown that data on the use of wearable technology to monitor physical activity in COPD patients are limited by the small number of studies and their heterogeneous study design. Further research and better-designed RCTs are needed to provide reliable results before physical activity monitors can be implemented routinely for COPD patients.


Assuntos
Actigrafia/instrumentação , Exercício , Monitores de Aptidão Física , Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Humanos , Valor Preditivo dos Testes , Prognóstico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/terapia , Reprodutibilidade dos Testes , Fatores de Tempo
9.
J Sports Med Phys Fitness ; 59(10): 1622-1627, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31311241

RESUMO

BACKGROUND: Activity tracking devices gain popularity in research, which is due to their multiple features (e.g. heart rate monitor, step count) and easy handling. Nevertheless, many devices used for research are lacking validation of specific features. This study aimed to assess the validity of the Polar M400© activity tracker to count steps in older adults and, therefore, compared it to a previously validated pedometer (Omron Walking Style©) and observed step count. METHODS: Thirty-two older adults (mean age: 74.8±5.9 years) walked at a self-selected, normal gait speed on a tartan track for 200 meters while wearing the activity tracker and the pedometer. Additionally, steps were counted manually. Data was analysed using Kruskal-Wallis test and Lin's concordance coefficient. Furthermore, Bland Altman plots were employed to evaluate accuracy of the activity tracker. RESULTS: Kruskal-Wallis test revealed significant differences between the step count of the activity tracker and the pedometer (P=0.011) but no further differences were observed. Lin's concordance showed a moderate correlation between activity tracker and pedometer (rc=0.561) and between pedometer and observed step count (rc=0.690). A high correlation was detected between activity tracker and observed step count (rc=0.802). Bland Altman plots revealed good accuracy of the activity tracker. CONCLUSIONS: The Polar M400© activity tracker accurately assesses steps during walking in older adults. Nevertheless, a slight overestimation compared to the pedometer was observed, which should be considered when using the activity tracker for tracking steps over a longer period of time.


Assuntos
Actigrafia/instrumentação , Monitores de Aptidão Física/normas , Determinação da Frequência Cardíaca/instrumentação , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Caminhada/fisiologia
10.
Int J Chron Obstruct Pulmon Dis ; 14: 1219-1228, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239657

RESUMO

Purpose: Seasons and weather conditions might influence participation in physical activity and contribute to differences between countries. This study aimed at investigating whether there were differences in physical activity levels between Norwegian, Danish and Australian people with chronic obstructive pulmonary disease (COPD), and establishing if any variations in physical activity were attributable to seasons. Patients and methods: A cross-sectional study where study subjects were people with COPD who participated in two separate clinical trials: the iTrain study (Norway, Denmark, and Australia) and the HomeBase study (Australia). Physical activity was objectively assessed with an activity monitor; variables were total energy expenditure, number of daily steps, awake sedentary time, light, and moderate-to-vigorous intensity physical activity. Differences in physical activity between countries and seasons were compared, with adjustment for disease severity. Results: In total, 168 participants were included from Norway (N=38), Denmark (N=36) and Australia (N=94). After controlling for disease severity, time spent in awake sedentary time was greater in Danish participants compared to the other countries (median 784 minutes/day [660-952] vs 775 minutes/day [626-877] for Norwegians vs 703 minutes/day [613-802] for Australians, P=0.013), whilst time spent in moderate to vigorous physical activity was lower (median 21 minutes/day [4-73] vs 30 minutes/day [7-93] for Norwegians vs 48 minutes/day [19-98] for Australians, P=0.024). Participants walked more during summer (median 3502 [1253-5407] steps/day) than in spring (median 2698 [1613-5207] steps/day), winter (median 2373 [1145-4206] steps/day) and autumn (median 1603 [738-4040] steps/day), regardless of geography. The median difference between summer and other seasons exceeded the minimal clinically important difference of 600 steps/day. However, the differences were not statistically significant (P=0.101). Conclusion: After controlling for disease severity, Danish participants spent more time in an awake sedentary state and less time in moderate to vigorous physical activity than their counterparts in Norway and Australia. People with COPD increased their physical activity in summer compared to other seasons. Weather conditions and seasonal variations may influence outcomes in clinical trials and health registries measuring physical activity over time, irrespective of the interventions delivered, and should be taken into account when interpreting results.


Assuntos
Exercício , Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Estações do Ano , Tempo (Meteorologia) , Actigrafia/instrumentação , Idoso , Estudos Transversais , Dinamarca , Tolerância ao Exercício , Feminino , Monitores de Aptidão Física , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Noruega , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Comportamento Sedentário , Fatores de Tempo , Vitória
11.
JMIR Mhealth Uhealth ; 7(6): e12190, 2019 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-31237237

RESUMO

BACKGROUND: Consumer wearables can provide a practical and accessible method of data collection in actigraphy research. However, as this area continues to grow, it is becoming increasingly important for researchers to be aware of the many challenges facing the capture of quality data using consumer wearables. OBJECTIVE: This study aimed to (1) present the challenges encountered by a research team in actigraphy data collection using a consumer wearable and (2) present considerations for researchers to apply in the pursuit of robust data using this approach. METHODS: The Nokia Go was deployed to 33 elite Gaelic footballers from a single team for a planned period of 14 weeks. A bring-your-own-device model was employed for this study where the Health Mate app was downloaded on participants' personal mobile phones and connected to the Nokia Go via Bluetooth. Retrospective evaluation of the researcher and participant experience was conducted through transactional data such as study logs and email correspondence. The participant experience of the data collection process was further explored through the design of a 34-question survey utilizing aspects of the Technology Acceptance Model. RESULTS: Researcher challenges included device disconnection, logistics and monitoring, and rectifying of technical issues. Participant challenges included device syncing, loss of the device, and wear issues, particularly during contact sport. Following disconnection issues, the data collection period was defined as 87 days for which there were 18 remaining participants. Average wear time was 79 out of 87 days (90%) and 20.8 hours per day. The participant survey found mainly positive results regarding device comfort, perceived ease of use, and perceived usefulness. CONCLUSIONS: Although this study did not encounter some of the common published barriers to wearable data collection, our experience was impacted by technical issues such as disconnection and syncing challenges, practical considerations such as loss of the device, issues with personal mobile phones in the bring-your-own-device model, and the logistics and resources required to ensure a smooth data collection with an active cohort. Recommendations for achieving high-quality data are made for readers to consider in the deployment of consumer wearables in research.


Assuntos
Comportamento do Consumidor/estatística & dados numéricos , Dispositivos Eletrônicos Vestíveis/estatística & dados numéricos , Actigrafia/instrumentação , Actigrafia/métodos , Actigrafia/estatística & dados numéricos , Estudos de Coortes , Monitores de Aptidão Física , Humanos , Estudos Retrospectivos , Inquéritos e Questionários
12.
JMIR Mhealth Uhealth ; 7(6): e12013, 2019 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-31199304

RESUMO

BACKGROUND: Mobile and wearable technology presents exciting opportunities for monitoring behavior using widely available sensor data. This could support clinical research and practice aimed at improving quality of life among the growing number of people with dementia. However, it requires suitable tools for measuring behavior in a natural real-life setting that can be easily implemented by others. OBJECTIVE: The objectives of this study were to develop and test a set of algorithms for measuring mobility and activity and to describe a technical setup for collecting the sensor data that these algorithms require using off-the-shelf devices. METHODS: A mobility measurement module was developed to extract travel trajectories and home location from raw GPS (global positioning system) data and to use this information to calculate a set of spatial, temporal, and count-based mobility metrics. Activity measurement comprises activity bout extraction from recognized activity data and daily step counts. Location, activity, and step count data were collected using smartwatches and mobile phones, relying on open-source resources as far as possible for accessing data from device sensors. The behavioral monitoring solution was evaluated among 5 healthy subjects who simultaneously logged their movements for 1 week. RESULTS: The evaluation showed that the behavioral monitoring solution successfully measures travel trajectories and mobility metrics from location data and extracts multimodal activity bouts during travel between locations. While step count could be used to indicate overall daily activity level, a concern was raised regarding device validity for step count measurement, which was substantially higher from the smartwatches than the mobile phones. CONCLUSIONS: This study contributes to clinical research and practice by providing a comprehensive behavioral monitoring solution for use in a real-life setting that can be replicated for a range of applications where knowledge about individual mobility and activity is relevant.


Assuntos
Técnicas de Observação do Comportamento/instrumentação , Demência/diagnóstico , Sistemas de Informação Geográfica/instrumentação , Dispositivos Eletrônicos Vestíveis/normas , Actigrafia/instrumentação , Actigrafia/métodos , Idoso , Idoso de 80 Anos ou mais , Técnicas de Observação do Comportamento/métodos , Técnicas de Observação do Comportamento/normas , Demência/fisiopatologia , Demência/psicologia , Feminino , Sistemas de Informação Geográfica/normas , Sistemas de Informação Geográfica/estatística & dados numéricos , Humanos , Masculino , Qualidade de Vida/psicologia , Dispositivos Eletrônicos Vestíveis/estatística & dados numéricos
13.
BMC Public Health ; 19(Suppl 2): 455, 2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159770

RESUMO

BACKGROUND: The central aim was to examine the accuracy of the full range of daily activities recorded in self-report time-use diaries against data from two objective passive data collection devices (wearable camera and accelerometer) serving as criterion reference instruments. This enabled systematic checks and comparisons on the timing, sequence and duration of activities recorded from the three data sources. METHODS: Participants (n = 148) were asked to complete a single-day self-report paper time-use diary designed for use in the Harmonised European Time Use Study (HETUS), while simultaneously wearing a camera that continuously recorded images of their activities, and an accelerometer tracking physical movement. In a reconstruction interview shortly after the data collection period, participants viewed the camera images to help researchers interpret the image sequences. Of the initial 148 recruits (multi-seed snowball sample, 59% women, aged 18-91, 43% > 40) 131 returned usable diary and camera records (of whom 124 also provided a usable whole-day accelerometer record. We compare time allocation estimates from the diary and camera records, and also match the diary and camera records to the simultaneously recorded accelerometer vector magnitudes. RESULTS: The data were examined at three analytic levels: aggregate, individual diarist and timeslot. The most important finding is that the estimates of mean daily time devoted to 8 of the 10 main activities differ by < 10% in the camera and diary records. The single case of major divergence (eating) can be explained by a systematic difference between the procedures followed by the self-reporting diarist and the observer coding the camera records. There are more substantial differences at the respondent level, paired t-tests showing significant differences in time spent in the 4/10 categories. 45% of all variation in the accelerometer vector magnitudes in the timeslots is explained by camera and diary records. Detailed activity classifications perform much better than METs as predictors of actigraphy. CONCLUSIONS: The comparison of the diary with the camera and accelerometer records strongly supports using diary methodology for studying the full range of daily activity, particularly at aggregate levels. Accelerometer data could be combined with diary measures to improve estimation of METs equivalents for various types of active and sedentary behaviour.


Assuntos
Acelerometria/estatística & dados numéricos , Actigrafia/instrumentação , Atividades Humanas/estatística & dados numéricos , Estudos de Tempo e Movimento , Dispositivos Eletrônicos Vestíveis/estatística & dados numéricos , Atividades Cotidianas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Comportamento Sedentário , Autorrelato , Adulto Jovem
14.
Nutrients ; 11(5)2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31137677

RESUMO

Wearable motion tracking sensors are now widely used to monitor physical activity, and have recently gained more attention in dietary monitoring research. The aim of this review is to synthesise research to date that utilises upper limb motion tracking sensors, either individually or in combination with other technologies (e.g., cameras, microphones), to objectively assess eating behaviour. Eleven electronic databases were searched in January 2019, and 653 distinct records were obtained. Including 10 studies found in backward and forward searches, a total of 69 studies met the inclusion criteria, with 28 published since 2017. Fifty studies were conducted exclusively in laboratory settings, 13 exclusively in free-living settings, and three in both settings. The most commonly used motion sensor was an accelerometer (64) worn on the wrist (60) or lower arm (5), while in most studies (45), accelerometers were used in combination with gyroscopes. Twenty-six studies used commercial-grade smartwatches or fitness bands, 11 used professional grade devices, and 32 used standalone sensor chipsets. The most used machine learning approaches were Support Vector Machine (SVM, n = 21), Random Forest (n = 19), Decision Tree (n = 16), Hidden Markov Model (HMM, n = 10) algorithms, and from 2017 Deep Learning (n = 5). While comparisons of the detection models are not valid due to the use of different datasets, the models that consider the sequential context of data across time, such as HMM and Deep Learning, show promising results for eating activity detection. We discuss opportunities for future research and emerging applications in the context of dietary assessment and monitoring.


Assuntos
Actigrafia/instrumentação , Comportamento Alimentar , Monitores de Aptidão Física , Atividade Motora , Transdutores , Extremidade Superior/fisiologia , Tecnologia sem Fio/instrumentação , Fenômenos Biomecânicos , Desenho de Equipamento , Humanos , Aprendizado de Máquina , Processamento de Sinais Assistido por Computador
15.
Nutrients ; 11(5)2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31137750

RESUMO

The present study aimed to assess the feasibility and reliability of an a3utomatic food intake measurement device in estimating energy intake from energy-dense foods. Eighteen volunteers aged 20-36 years were recruited from the University of Padova. The device used in the present study was the Bite Counter (Bite Technologies, Pendleton, USA). The rationale of the device is that the wrist movements occurring in the act of bringing food to the mouth present unique patterns that are recognized and recorded by the Bite Counter. Subjects were asked to wear the Bite Counter on the wrist of the dominant hand, to turn the device on before the first bite and to turn it off once he or she finished his or her meal. The accuracy of caloric intake was significantly different among the methods used. In addition, the device's accuracy in estimating energy intake varied according to the type and amount of macronutrients present, and the difference was independent of the number of bites recorded. Further research is needed to overcome the current limitations of wearable devices in estimating caloric intake, which is not independent of the food being eaten.


Assuntos
Actigrafia/instrumentação , Ingestão de Alimentos , Ingestão de Energia , Monitores de Aptidão Física , Atividade Motora , Valor Nutritivo , Punho/fisiologia , Adulto , Fenômenos Biomecânicos , Desenho de Equipamento , Estudos de Viabilidade , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Adulto Jovem
16.
Clin Rehabil ; 33(8): 1382-1390, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30955362

RESUMO

OBJECTIVE: To test if pedometers, as a motivational tool, could affect mobility outcomes in inpatient rehabilitation. DESIGN: Randomized controlled clinical trial. SETTING: Subacute hospital rehabilitation unit in Australia. PARTICIPANTS: A total of 78 participants with reduced mobility and clinician-determined capacity to improve. INTERVENTIONS: Both groups received usual care. For the intervention group, a pedometer was worn on the hip with the step count visible to participant and recorded daily on an exercise log. For the control group, a pedometer fixed shut was worn on the hip and they recorded estimated distances walked on an exercise log. MAIN MEASURES: Primary outcome was functional mobility - De Morton Mobility Index. Secondary outcome measures were walking velocity, functional independence measure, time spent upright and daily step count. RESULTS: Significant improvements over time (P < 0.001) in functional mobility, comfortable walking velocity and functional independence measure were not influenced by the intervention. The daily average upright time (hours) in the first week of intervention was different (P = 0.004) between the intervention group (median, interquartile range (IQR): 1.67, 1.77) compared to the control group (median, IQR: 1.12, 0.82). CONCLUSION: Pedometers as a motivational tool without targets do not improve functional mobility in this population. Pedometers may improve daily upright time in this setting.


Assuntos
Actigrafia/instrumentação , Velocidade de Caminhada , Caminhada , Idoso , Avaliação da Deficiência , Feminino , Hospitalização , Humanos , Masculino , Limitação da Mobilidade , Motivação , Método Simples-Cego
17.
J Sports Sci ; 37(16): 1910-1918, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31012798

RESUMO

This study aimed to validate the Sedentary Sphere posture classification method from wrist-worn accelerometers in children. Twenty-seven 9-10-year-old children wore ActiGraph GT9X (AG) and GENEActiv (GA) accelerometers on both wrists, and activPAL on the thigh while completing prescribed activities: five sedentary activities, standing with a phone, walking (criterion for all 7: observation) and 10-min free-living play (criterion: activPAL). In an independent sample, 21 children wore AG and GA accelerometers on the non-dominant wrist and activPAL for two days of free-living. Per cent accuracy, pairwise 95% equivalence tests (±10% equivalence zone) and intra-class correlation coefficients (ICC) analyses were completed. Accuracy was similar, for prescribed activities irrespective of brand (non-dominant wrist: 77-78%; dominant wrist: 79%). Posture estimates were equivalent between wrists within brand (±6%, ICC > 0.81, lower 95% CI ≥ 0.75), between brands worn on the same wrist (±5%, ICC ≥ 0.84, lower 95% CI ≥ 0.80) and between brands worn on opposing wrists (±6%, ICC ≥ 0.78, lower 95% CI ≥ 0.72). Agreement with activPAL during free-living was 77%, but sedentary time was underestimated by 7% (GA) and 10% (AG). The Sedentary Sphere can be used to classify posture from wrist-worn AG and GA accelerometers for group-level estimates in children, but future work is needed to improve the algorithm for better individual-level results.


Assuntos
Actigrafia/instrumentação , Monitores de Aptidão Física , Postura , Comportamento Sedentário , Atividades Cotidianas , Algoritmos , Criança , Desenho de Equipamento , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Coxa da Perna , Punho
18.
J Sports Sci ; 37(16): 1899-1909, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31002287

RESUMO

Improving sedentary measurement is critical to understanding sedentary-health associations in youth. This study assessed agreement between the thigh-worn activPAL and commonly used hip-worn ActiGraph accelerometer methods for assessing sedentary patterns in children. Both devices were worn by 8-12-year-olds (N = 195) for 4.6 ± 1.9 days. Two ActiGraph cut-points were applied to two epoch durations: ≤25 counts (c)/15 s, ≤75c/15s, ≤100c/60s, and ≤300c/60s. Bias, mean absolute deviation (MAD), and intraclass correlation coefficients (ICCs) tested agreement between devices for total sedentary time and 11 sedentary pattern variables (usual bout duration, sedentary time accumulated in various bout durations, breaks/day, break rate, and alpha). For most sedentary pattern variables, ActiGraph 25c/15s, 75c/15s, and 100c/60s had poor ICCs, with bias and MAD >20%. ActiGraph 300c/60s had a better agreement than the other cut-points, but all ICCs were <0.587. ActiGraph underestimated sedentary time in longer bouts and usual bout duration, and overestimated sedentary time in shorter bouts, breaks/day, and alpha. For total sedentary time, ActiGraph 25c/15s, 300c/60s, and 75c/15s had good/fair ICCs, with bias and MAD <20%. Sedentary patterns derived from two commonly used ActiGraph cut-points did not appear to reflect postural changes. These differences between measurement devices should be considered when interpreting findings from sedentary pattern studies.


Assuntos
Actigrafia/instrumentação , Monitores de Aptidão Física , Postura/fisiologia , Comportamento Sedentário , Criança , Desenho de Equipamento , Feminino , Quadril , Humanos , Masculino , Reprodutibilidade dos Testes , Coxa da Perna
19.
Clin Physiol Funct Imaging ; 39(4): 276-283, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30980611

RESUMO

The purpose of this study was to investigate the effect of different band-pass filters on the measurement bias with ActiGraph counts during high speed running and for estimating free-living vigorous physical activity (VPA). Two alternative band-pass filters were designed, extending the original frequency range from 0·29 to 1·66 Hz (AG) to 0·29-4 Hz (AC4) and 0·29-10 Hz (AC10). Sixty-two subjects in three age groups participated in a structured locomotion protocol consisting of multiple walking and running speeds. The time spent in free-living VPA using the three different band-pass filters were evaluated in 1121 children. Band-pass filter specific intensity cut-points from both linear regression and ROC analysis was identified from a calibration experiment using indirect calorimetry. The ActiGraph GT3X+ device recording raw acceleration at 30 Hz was used in all experiments. The linear association between counts and running speed was negative for AG but positive for AC4 and AC10 across all age groups. The time spent in free-living VPA was similar for all band-pass filters. Considering higher frequency information in the generation of ActiGraph counts with a hip/waist worn device reduces the measurement bias with running above 10 km·h-1 . However, additional developments are required to accurately capture all VPA, including intermittent activities.


Assuntos
Actigrafia/instrumentação , Monitores de Aptidão Física , Corrida , Processamento de Sinais Assistido por Computador , Caminhada , Adolescente , Adulto , Algoritmos , Calorimetria Indireta , Criança , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Fatores de Tempo , Adulto Jovem
20.
Artigo em Inglês | MEDLINE | ID: mdl-30863042

RESUMO

Background: The constructs and interdependency of physical behaviors are not well described and the complexity of physical activity (PA) data analysis remains unexplored in COPD. This study examined the interrelationships of 24-hour physical behaviors and investigated their associations with participant characteristics for individuals with mild-moderate airflow obstruction and healthy control subjects. Patients and methods: Vigorous PA (VPA), moderate-to-vigorous PA (MVPA), light PA (LPA), stationary time (ST), average movement intensity (vector magnitude counts per minute), and sleep duration for 109 individuals with COPD and 135 healthy controls were obtained by wrist-worn accelerometry. Principal components analysis (PCA) examined interrelationships of physical behaviors to identify distinct behavioral constructs. Using the PCA component loadings, linear regressions examined associations with participant (+, positive correlation; -, negative correlation), and were compared between COPD and healthy control groups. Results: For both groups PCA revealed ST, LPA, and average movement intensity as distinct behavioral constructs to MVPA and VPA, labeled "low-intensity movement" and "high-intensity movement," respectively. Sleep was also found to be its own distinct behavioral construct. Results from linear regressions supported the identification of distinct behavioral constructs from PCA. In COPD, low-intensity movement was associated with limitations with mobility (-), daily activities (-), health status (+), and body mass index (BMI) (-) independent of high-intensity movement and sleep. High-intensity movement was associated with age (-) and self-care limitations (-) independent of low-intensity movement and sleep. Sleep was associated with gender (0= female, 1= male; [-]), lung function (-), and percentage body fat (+) independent of low-intensity and high-intensity movement. Conclusion: Distinct behavioral constructs comprising the 24-hour day were identified as "low-intensity movement," "high-intensity movement," and "sleep" with each construct independently associated with different participant characteristics. Future research should determine whether modifying these behaviors improves health outcomes in COPD.


Assuntos
Actigrafia/instrumentação , Ciclos de Atividade , Exercício , Monitores de Aptidão Física , Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Comportamento Sedentário , Sono , Adulto , Idoso , Estudos de Casos e Controles , Estudos Transversais , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Análise de Componente Principal , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/psicologia , Fatores de Tempo
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