scholarly journals Step and Distance Measurement From a Low-Cost Consumer-Based Hip and Wrist Activity Monitor: Protocol for a Validity and Reliability Assessment (Preprint)

2020 ◽  
Author(s):  
Thomas Carlin ◽  
Nicolas Vuillerme
Keyword(s):  
Walking Speed ◽  
Low Cost ◽  
Activity Monitor ◽  
Distance Measurement ◽  
Step Count ◽  
Mobile Technologies ◽  
Experimental Session ◽  
Validity And Reliability ◽  
Activity Monitors ◽  
Study Results

BACKGROUND Self-tracking via wearable and mobile technologies is becoming an essential part of personal health management. At this point, however, little information is available to substantiate the validity and reliability of low-cost consumer-based hip and wrist activity monitors, with regard more specifically to the measurements of step counts and distance traveled while walking. OBJECTIVE The aim of our study is to assess the validity and reliability of step and distance measurement from a low-cost consumer-based hip and wrist activity monitor specific in various walking conditions that are commonly encountered in daily life. Specifically, this study is designed to evaluate whether and to what extent validity and reliability could depend on the sensor placement on the human body and the walking task being performed. METHODS Thirty healthy participants will be instructed to wear four PBN 2433 (Nakosite) activity monitors simultaneously, with one placed on each hip and each wrist. Participants will attend two experimental sessions separated by 1 week. During each experimental session, two separate studies will be performed. In study 1, participants will be instructed to complete a 2-minute walk test along a 30-meter indoor corridor under 3 walking speeds: very slow, slow, and usual speed. In study 2, participants will be required to complete the following 3 conditions performed at usual walking speed: walking on flat ground, upstairs, and downstairs. Activity monitor measured step count and distance values will be computed along with the actual step count (determined from video recordings) and distance (measured using a measuring tape) to determine validity and reliability for each activity monitor placement and each walking condition. RESULTS Participant recruitment and data collection began in January 2020. As of June 2020, we enrolled 8 participants. Dissemination of study results in peer-reviewed journals is expected in spring 2021. CONCLUSIONS To the best of our knowledge, this is the first study that examines the validity and reliability of step and distance measurement during walking using the PBN 2433 (Nakosite) activity monitor. Results of this study will provide beneficial information on the effects of activity monitor placement, walking speed, and walking tasks on the validity and reliability of step and distance measurement. We believe such information is of utmost importance to general consumers, clinicians, and researchers. INTERNATIONAL REGISTERED REPORT DERR1-10.2196/21262

scholarly journals Step and Distance Measurement From a Low-Cost Consumer-Based Hip and Wrist Activity Monitor: Protocol for a Validity and Reliability Assessment

10.2196/21262 ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. e21262
Author(s):  
Thomas Carlin ◽  
Nicolas Vuillerme
Keyword(s):  
Walking Speed ◽  
Low Cost ◽  
Activity Monitor ◽  
Distance Measurement ◽  
Step Count ◽  
Mobile Technologies ◽  
Experimental Session ◽  
Validity And Reliability ◽  
Activity Monitors ◽  
Study Results

Background Self-tracking via wearable and mobile technologies is becoming an essential part of personal health management. At this point, however, little information is available to substantiate the validity and reliability of low-cost consumer-based hip and wrist activity monitors, with regard more specifically to the measurements of step counts and distance traveled while walking. Objective The aim of our study is to assess the validity and reliability of step and distance measurement from a low-cost consumer-based hip and wrist activity monitor specific in various walking conditions that are commonly encountered in daily life. Specifically, this study is designed to evaluate whether and to what extent validity and reliability could depend on the sensor placement on the human body and the walking task being performed. Methods Thirty healthy participants will be instructed to wear four PBN 2433 (Nakosite) activity monitors simultaneously, with one placed on each hip and each wrist. Participants will attend two experimental sessions separated by 1 week. During each experimental session, two separate studies will be performed. In study 1, participants will be instructed to complete a 2-minute walk test along a 30-meter indoor corridor under 3 walking speeds: very slow, slow, and usual speed. In study 2, participants will be required to complete the following 3 conditions performed at usual walking speed: walking on flat ground, upstairs, and downstairs. Activity monitor measured step count and distance values will be computed along with the actual step count (determined from video recordings) and distance (measured using a measuring tape) to determine validity and reliability for each activity monitor placement and each walking condition. Results Participant recruitment and data collection began in January 2020. As of June 2020, we enrolled 8 participants. Dissemination of study results in peer-reviewed journals is expected in spring 2021. Conclusions To the best of our knowledge, this is the first study that examines the validity and reliability of step and distance measurement during walking using the PBN 2433 (Nakosite) activity monitor. Results of this study will provide beneficial information on the effects of activity monitor placement, walking speed, and walking tasks on the validity and reliability of step and distance measurement. We believe such information is of utmost importance to general consumers, clinicians, and researchers. International Registered Report Identifier (IRRID) DERR1-10.2196/21262

scholarly journals Formative Evaluation of Consumer-Grade Activity Monitors Worn by Older Adults: Test-Retest Reliability and Criterion Validity of Step Counts (Preprint)

2019 ◽  
Author(s):  
Stephanie A Maganja ◽  
David C Clarke ◽  
Scott A Lear ◽  
Dawn C Mackey
Keyword(s):  
Older Adults ◽  
Activity Monitor ◽  
Criterion Validity ◽  
Step Count ◽  
Retest Reliability ◽  
Activity Monitors ◽  
Limited Mobility ◽  
Step Counts ◽  
Test Retest Reliability ◽  
Mobility Status

BACKGROUND To assess whether commercial-grade activity monitors are appropriate for measuring step counts in older adults, it is essential to evaluate their measurement properties in this population. OBJECTIVE This study aimed to evaluate test-retest reliability and criterion validity of step counting in older adults with self-reported intact and limited mobility from 6 commercial-grade activity monitors: Fitbit Charge, Fitbit One, Garmin vívofit 2, Jawbone UP2, Misfit Shine, and New-Lifestyles NL-1000. METHODS For test-retest reliability, participants completed two 100-step overground walks at a usual pace while wearing all monitors. We tested the effects of the activity monitor and mobility status on the absolute difference in step count error (%) and computed the standard error of measurement (SEM) between repeat trials. To assess criterion validity, participants completed two 400-meter overground walks at a usual pace while wearing all monitors. The first walk was continuous; the second walk incorporated interruptions to mimic the conditions of daily walking. Criterion step counts were from the researcher tally count. We estimated the effects of the activity monitor, mobility status, and walk interruptions on step count error (%). We also generated Bland-Altman plots and conducted equivalence tests. RESULTS A total of 36 individuals participated (n=20 intact mobility and n=16 limited mobility; 19/36, 53% female) with a mean age of 71.4 (SD 4.7) years and BMI of 29.4 (SD 5.9) kg/m<sup>2</sup>. Considering test-retest reliability, there was an effect of the activity monitor (<i>P</i>&lt;.001). The Fitbit One (1.0%, 95% CI 0.6% to 1.3%), the New-Lifestyles NL-1000 (2.6%, 95% CI 1.3% to 3.9%), and the Garmin vívofit 2 (6.0%, 95 CI 3.2% to 8.8%) had the smallest mean absolute differences in step count errors. The SEM values ranged from 1.0% (Fitbit One) to 23.5% (Jawbone UP2). Regarding criterion validity, all monitors undercounted the steps. Step count error was affected by the activity monitor (<i>P</i>&lt;.001) and walk interruptions (<i>P</i>=.02). Three monitors had small mean step count errors: Misfit Shine (−1.3%, 95% CI −19.5% to 16.8%), Fitbit One (−2.1%, 95% CI −6.1% to 2.0%), and New-Lifestyles NL-1000 (−4.3%, 95 CI −18.9% to 10.3%). Mean step count error was larger during interrupted walking than continuous walking (−5.5% vs −3.6%; <i>P</i>=.02). Bland-Altman plots illustrated nonsystematic bias and small limits of agreement for Fitbit One and Jawbone UP2. Mean step count error lay within an equivalence bound of ±5% for Fitbit One (<i>P</i>&lt;.001) and Misfit Shine (<i>P</i>=.001). CONCLUSIONS Test-retest reliability and criterion validity of step counting varied across 6 consumer-grade activity monitors worn by older adults with self-reported intact and limited mobility. Walk interruptions increased the step count error for all monitors, whereas mobility status did not affect the step count error. The hip-worn Fitbit One was the only monitor with high test-retest reliability and criterion validity.

scholarly journals The Accuracy of Fitness Trackers Varies with Their Location on the Body (P16-019-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Donald Kotler ◽  
Christopher Wu ◽  
Kwame Thompson ◽  
Zachary Jenkins ◽  
Rafay Latif ◽  
...  
Keyword(s):  
Low Cost ◽  
Smartphone Application ◽  
Activity Monitor ◽  
The Body ◽  
Daily Step ◽  
Activity Monitors ◽  
Step Counts ◽  
Funding Sources ◽  
Fitness Tracker ◽  
Fitness Trackers

Abstract Objectives Advances in low cost physiologic monitoring devices have led to the possibility of making objective measures of physical activity in clinical practice. In a previous study, total daily step counts measured by a pedometer were lower than those obtained from a smartphone application, while exercise step counts were similar. It is uncertain which is the more accurate value for total daily steps. Most pedometers are worn on the torso while most fitness trackers are worn on the wrist. Overestimation of daily step counts by wrist-worn fitness trackers have been demonstrated by others. Specific aims: To estimate the precision of pedometer step counts measured during a 400 m walk. To compare daily step counts using a pedometer on the torso and fitness trackers worn on the wrist or on the torso. Methods Six subjects wore a pedometer (Omron Alvita HJ327T) and an activity monitor (Letscom Fitness Tracker ID130Plus ColorHR). Each subject wore the pedometer on the torso and two activity monitors for 3 days; both activity monitors on one wrist, one activity monitor on a wrist and the other on the torso (belt), and the reverse positions of the activity monitors. In addition, each subject completed a 400 m walk on two occasions and walked a total of 500 counted steps. Total and 400 m step counts for the pedometer and activity monitor and the test/retest results during the 400 m walk were compared by paired T test and inter-individual variations were compared by one-way analysis of variance (ANOVA). Results Pedometer-measured and counted steps differed by 1%. Test/retest pedometer step counts and times to completion for the 400 m walk both differed by 1.4%. Wrist-worn fitness trackers produced higher step counts than did the pedometers (18.6 + 0.18%, P < 0.002). Fitness trackers worn on the torso gave lower step counts than did the pedometer (−9.2 + 0.08%, P < 0.001). The inter-individual differences were not statistically significant for wrist or torso step counts. Conclusions A pedometer worn on the torso is a precise measure of step counts during a 400 m walk and accurate compared to counted steps. Wrist-worn fitness trackers overestimate total daily step counts, at least compared to a pedometer. The location of the fitness tracker on the body greatly influences its estimation of total daily step counts. Funding Sources Discretionary funds.

scholarly journals Formative Evaluation of Consumer-Grade Activity Monitors Worn by Older Adults: Test-Retest Reliability and Criterion Validity of Step Counts

10.2196/16537 ◽  
2020 ◽  
Vol 4 (8) ◽  
pp. e16537 ◽  
Author(s):  
Stephanie A Maganja ◽  
David C Clarke ◽  
Scott A Lear ◽  
Dawn C Mackey
Keyword(s):  
Older Adults ◽  
Activity Monitor ◽  
Criterion Validity ◽  
Step Count ◽  
Retest Reliability ◽  
Activity Monitors ◽  
Limited Mobility ◽  
Step Counts ◽  
Test Retest Reliability ◽  
Mobility Status

Background To assess whether commercial-grade activity monitors are appropriate for measuring step counts in older adults, it is essential to evaluate their measurement properties in this population. Objective This study aimed to evaluate test-retest reliability and criterion validity of step counting in older adults with self-reported intact and limited mobility from 6 commercial-grade activity monitors: Fitbit Charge, Fitbit One, Garmin vívofit 2, Jawbone UP2, Misfit Shine, and New-Lifestyles NL-1000. Methods For test-retest reliability, participants completed two 100-step overground walks at a usual pace while wearing all monitors. We tested the effects of the activity monitor and mobility status on the absolute difference in step count error (%) and computed the standard error of measurement (SEM) between repeat trials. To assess criterion validity, participants completed two 400-meter overground walks at a usual pace while wearing all monitors. The first walk was continuous; the second walk incorporated interruptions to mimic the conditions of daily walking. Criterion step counts were from the researcher tally count. We estimated the effects of the activity monitor, mobility status, and walk interruptions on step count error (%). We also generated Bland-Altman plots and conducted equivalence tests. Results A total of 36 individuals participated (n=20 intact mobility and n=16 limited mobility; 19/36, 53% female) with a mean age of 71.4 (SD 4.7) years and BMI of 29.4 (SD 5.9) kg/m2. Considering test-retest reliability, there was an effect of the activity monitor (P<.001). The Fitbit One (1.0%, 95% CI 0.6% to 1.3%), the New-Lifestyles NL-1000 (2.6%, 95% CI 1.3% to 3.9%), and the Garmin vívofit 2 (6.0%, 95 CI 3.2% to 8.8%) had the smallest mean absolute differences in step count errors. The SEM values ranged from 1.0% (Fitbit One) to 23.5% (Jawbone UP2). Regarding criterion validity, all monitors undercounted the steps. Step count error was affected by the activity monitor (P<.001) and walk interruptions (P=.02). Three monitors had small mean step count errors: Misfit Shine (−1.3%, 95% CI −19.5% to 16.8%), Fitbit One (−2.1%, 95% CI −6.1% to 2.0%), and New-Lifestyles NL-1000 (−4.3%, 95 CI −18.9% to 10.3%). Mean step count error was larger during interrupted walking than continuous walking (−5.5% vs −3.6%; P=.02). Bland-Altman plots illustrated nonsystematic bias and small limits of agreement for Fitbit One and Jawbone UP2. Mean step count error lay within an equivalence bound of ±5% for Fitbit One (P<.001) and Misfit Shine (P=.001). Conclusions Test-retest reliability and criterion validity of step counting varied across 6 consumer-grade activity monitors worn by older adults with self-reported intact and limited mobility. Walk interruptions increased the step count error for all monitors, whereas mobility status did not affect the step count error. The hip-worn Fitbit One was the only monitor with high test-retest reliability and criterion validity.

The Effect of BMI and Walking Speed on Step Count Validity of Wearable Activity Monitors

2010 ◽  
Vol 42 ◽  
pp. 489 ◽  
Author(s):  
Yuri Feito ◽  
Brian M. Tyo ◽  
David R. Bassett ◽  
Dixie L. Thompson
Keyword(s):  
Walking Speed ◽  
Step Count ◽  
Activity Monitors

Associations of Activity Monitor Output and an Estimate of Aerobic Fitness With Pulse Wave Velocities: The Nakanojo Study

2015 ◽  
Vol 12 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Makoto Ayabe ◽  
Sungjin Park ◽  
Roy J. Shephard ◽  
Yukitoshi Aoyagi
Keyword(s):  
Physical Activity ◽  
Arterial Stiffness ◽  
Aerobic Fitness ◽  
Walking Speed ◽  
Pulse Wave ◽  
Activity Monitor ◽  
Step Count ◽  
Daily Step ◽  
Metabolic Equivalents ◽  
Daily Step Count

Background:We examined the relative contributions of habitual physical activity and aerobic fitness to the prevention of arteriosclerosis.Methods:Elderly individuals (97 men and 109 women, aged > 65 y) each wore a uniaxial activity monitor continuously for 1 year, with activity data summarized as an average daily step count and duration of activity > 3 metabolic equivalents (METs). Aerobic fitness was assessed by a standardized 5-m walking test measure of maximal walking speed. Central arterial stiffness was determined using an automatic waveform analyzer measure of cardio-femoral pulse wave velocity (cfPWV).Results:The cfPWV was negatively associated with daily step count, duration of activity > 3 METs, and maximal walking speed (P < .05). Multiple stepwise regression analysis revealed that the step count, duration of activity > 3 METs, and maximal walking speed were all significant predictors of cfPWV, accounting for 11%, 7%, and 4% of total variance, respectively.Conclusions:In contrast to findings from studies using potentially fallible questionnaires, our data suggest that a measure of health (arterial stiffness) is more closely related to objective measures of physical activity than to an estimate of aerobic fitness.

scholarly journals Accuracy of 2 Activity Monitors in Detecting Steps in People With Stroke and Traumatic Brain Injury

2014 ◽  
Vol 94 (2) ◽  
pp. 222-229 ◽  
Author(s):  
George D. Fulk ◽  
Stephanie A. Combs ◽  
Kelly A. Danks ◽  
Coby D. Nirider ◽  
Bhavana Raja ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Low Cost ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Activity Monitor ◽  
Mean Difference ◽  
Cross Sectional ◽  
Activity Monitors ◽  
Walking Activity

Background Advances in sensor technologies and signal processing techniques provide a method to accurately measure walking activity in the home and community. Activity monitors geared toward consumer or patient use may be an alternative to more expensive monitors designed for research to measure stepping activity. Objective The objective of this study was to examine the accuracy of 2 consumer/patient activity monitors, the Fitbit Ultra and the Nike+ Fuelband, in identifying stepping activity in people with stroke and traumatic brain injury (TBI). Secondarily, the study sought to compare the accuracy of these 2 activity monitors with that of the StepWatch Activity Monitor (SAM) and a pedometer, the Yamax Digi-Walker SW-701 pedometer (YDWP). Design A cross-sectional design was used for this study. Method People with chronic stroke and TBI wore the 4 activity monitors while they performed the Two-Minute Walk Test (2MWT), during which they were videotaped. Activity monitor estimated steps taken were compared with actual steps taken counted from videotape. Accuracy and agreement between activity monitor estimated steps and actual steps were examined using intraclass correlation coefficients (ICC [2,1]) and the Bland-Altman method. Results The SAM demonstrated the greatest accuracy (ICC [2,1]=.97, mean difference between actual steps and SAM estimated steps=4.7 steps) followed by the Fitbit Ultra (ICC [2,1]=.73, mean difference between actual steps and Fitbit Ultra estimated steps=−9.7 steps), the YDWP (ICC [2,1]=.42, mean difference between actual steps and YDWP estimated steps=−28.8 steps), and the Nike+ Fuelband (ICC [2,1]=.20, mean difference between actual steps and Nike+ Fuelband estimated steps=−66.2 steps). Limitations Walking activity was measured over a short distance in a closed environment, and participants were high functioning ambulators, with a mean gait speed of 0.93 m/s. Conclusions The Fitbit Ultra may be a low-cost alternative to measure the stepping activity in level, predictable environments of people with stroke and TBI who can walk at speeds ≥0.58 m/s.

POTENTIAL EVALUATION OF YELLOW COTTON (COCHLOSPERMUM REGIUM) PIGMENTS FOR DYE SENSITIZED SOLAR CELLS APPLICATION

2020 ◽  
pp. 16-21
Author(s):  
PHITCHAPHORN KHAMMEE ◽  
YUWALEE UNPAPROM ◽  
UBONWAN SUBHASAEN ◽  
RAMESHPRABU RAMARAJ
Keyword(s):  
Solar Cells ◽  
Low Cost ◽  
Dye Sensitized Solar Cells ◽  
Photoelectric Conversion Efficiency ◽  
Photoelectric Conversion ◽  
Plant Materials ◽  
Natural Pigments ◽  
Dye Sensitized ◽  
Study Results ◽  
Sensitized Solar Cells

Recently, dye-sensitized solar cells (DSSC) have concerned significant attention attributable to their material preparation process, architectural and environmental compatibility, also low cost and effective photoelectric conversion efficiency. Therefore, this study aimed to use potential plant materials for DSSC. This research presents the extraction of natural pigments from yellow cotton flowers (Cochlospermum regium). In addition, the natural pigments were revealed that outstanding advantages, including a wide absorption range (visible light), easy extraction method, safe, innocuous pigments, inexpensive, complete biodegradation and ecofriendly. Methanol was used as a solvent extraction for the yellow cotton flower. The chlorophylls and carotenoid pigments extractions were estimated by a UV-visible spectrometer. The chlorophyll-a, chlorophyll-b, and carotenoid yield were 0.719±0.061 µg/ml, 1.484±0.107 µg/ml and 7.743±0.141 µg/ml, respectively. Thus, this study results suggested that yellow cotton flowers containing reasonable amounts appealable in the DSSC production.

The Use of Mobile Technology in Management and Risk Control in the Supply Chain

2014 ◽  
Vol 22 (1) ◽  
pp. 14-33 ◽  
Author(s):  
Amarolinda Zanela Klein ◽  
Eliane Gomes da Costa ◽  
Luciana Marques Vieira ◽  
Rafael Teixeira
Keyword(s):  
Supply Chain ◽  
Risk Reduction ◽  
Mobile Technology ◽  
Technology Use ◽  
Single Case ◽  
Risk Control ◽  
Mobile Technologies ◽  
Food Markets ◽  
Safety Risks ◽  
Study Results

The use of mobile technologies is important for Supply Chain Management (SCM) because these technologies allow for a ubiquitous flow of information, higher agility and risk reduction in supply chains. In food markets, these issues are particularly relevant due to food safety risks. The main goal of this paper is to analyze the use of mobile technology for management and risk control in the Brazilian beef supply chain, since Brazil is one of the main producers and beef exporters in the world. The research method was a single case study. Results show the actual level of mobile technology use; drivers and barriers to mobile technology adoption and how mobile technology is applied to beef traceability and risk reduction along the chain. The authors propose a framework that links the issues of mobile technology use for SCM and risk control, considering the context of a developing country such as Brazil.

scholarly journals Tower Crane Location Optimization for Heavy Unit Lifting in High-Rise Modular Construction

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 121
Author(s):  
Hosang Hyun ◽  
Moonseo Park ◽  
Dowan Lee ◽  
Jeonghoon Lee
Keyword(s):  
Low Cost ◽  
Modular Construction ◽  
Algorithm Optimization ◽  
Location Selection ◽  
Project Completion ◽  
High Rise ◽  
Tower Crane ◽  
Proposed Model ◽  
Study Results ◽  
Crane Selection

Modular construction, which involves unit production in factories and on-site work, has benefits such as low cost, high quality, and short duration, resulting from the controlled factory environment utilized. An efficient tower crane lifting plan ensures successful high-rise modular project completion. For improved efficiency, the lifting plan should minimize the reaching distance of the tower crane, because this distance directly affects the tower crane capacity, which is directly related to crane operation cost. In situations where units are lifted from trailers, the trailer-to-tower crane distance can have a significant impact on the tower crane operation efficiency. However, optimization of this distance to improve efficiency has not been sufficiently considered. This research proposes a genetic algorithm optimization model that suggests optimized tower crane and trailer locations. The case study results show that through the proposed model, the project manager can reflect the optimal location selection and optimal tower crane selection options with minimal cost.

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