The Cosmed K4 Telemetry System as an Accurate Device for Oxygen Uptake Measurements during Exercise

Hausswirth, Christophe; Bigard, A. X.; Chevalier, J.-M.

doi:10.1055/s-2007-972662

Cited by 165 publications

(108 citation statements)

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“…In this study, the Actiheart was set up to record in IBI logging mode, storing activity every 15 s. Oxygen consumption (VO 2 ) and carbon dioxide (VCO 2 ) production rates were measured breath-by-breath with a portable indirect calorimetry system (K4b 2 , Cosmed s.r.l. Rome, Italy), previously validated (Hausswirth et al, 1997;McLaughlin et al, 2001). On all test days, gas analysers were calibrated against room air and a standard gas (16% O 2 , 5% CO 2 ) before the first test, at least 45 min after the equipment had been turned on.…”

Section: Prediction Of Pai During Walking and Runningmentioning

confidence: 99%

Reliability and validity of the combined heart rate and movement sensor Actiheart

et al. 2005

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Accurate quantification of physical activity energy expenditure is a key part of the effort to understand disorders of energy metabolism. The Actiheart, a combined heart rate (HR) and movement sensor, is designed to assess physical activity in populations. Objective: To examine aspects of Actiheart reliability and validity in mechanical settings and during walking and running. Methods: In eight Actiheart units, technical reliability (coefficients of variation, CV) and validity for movement were assessed with sinusoid accelerations (0.1-20 m/s 2 ) and for HR by simulated R-wave impulses (25-250 bpm). Agreement between Actiheart and ECG was determined during rest and treadmill locomotion (3.2-12.1 km/h). Walking and running intensity (in J/ min/kg) was assessed with indirect calorimetry in 11 men and nine women (26-50 y, 20-29 kg/m 2 ) and modelled from movement, HR, and movement þ HR by multiple linear regression, adjusting for sex. Results: Median intrainstrument CV was 0.5 and 0.03% for movement and HR, respectively. Corresponding interinstrument CV values were 5.7 and 0.03% with some evidence of heteroscedasticity for movement. The linear relationship between movement and acceleration was strong (R 2 ¼ 0.99, Po0.001). Simulated R-waves were detected within 1 bpm from 30 to 250 bpm. The 95% limits of agreement between Actiheart and ECG were À4.2 to 4.3 bpm. Correlations with intensity were generally high (R 2 40.84, Po0.001) but significantly highest when combining HR and movement (SEEo1 MET). Conclusions: The Actiheart is technically reliable and valid. Walking and running intensity may be estimated accurately but further studies are needed to assess validity in other activities and during free-living. Sponsorship: The study received financial support from the Wellcome Trust and SB was supported by a scholarship from Unilever, UK.

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Section: Prediction Of Pai During Walking and Runningmentioning

confidence: 99%

Reliability and validity of the combined heart rate and movement sensor Actiheart

et al. 2005

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“…El K4 system ha sido validado para medición del consumo de oxígeno y la frecuencia cardiaca en ejercicio 19 . Antes de cada ensayo se realizó la calibración del equipo para el análisis de O 2 y CO 2 , con mezcla de gases.…”

Section: Instrumentosunclassified

Tiempo máximo aceptable de trabajo para tareas ejecutadas con miembros superiores e inferiores

Velásquez

2015

revsal

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RESUMENIntroducción: La carga física de trabajo es uno de los principales factores de riesgo a los que se enfrentan los trabajadores. En la actualidad los métodos propuestos para evaluar la carga física dinámica contemplan el trabajo con todo el cuerpo y no discriminan por segmentos corporales. Objetivo: Determinar el tiempo máximo aceptable de trabajo cuando el trabajo se ejecuta con todo el cuerpo, con los miembros superiores o los miembros inferiores. Métodos: Se realizó medición de consumo de oxígeno mediante ergoespirometria y monitorización de la frecuencia cardiaca en 30 trabajadores expuestos a diversas cargas ejecutadas con todo el cuerpo, miembros inferiores y miembros superiores. Se determinó el umbral anaeróbico por coeficiente respiratorio, el cual sirvió de base para de determinación del tiempo máximo aceptable de trabajo. Resultados: Los tiempos máximos aceptables de trabajo fueron similares para tareas con todo el cuerpo y con miembros inferiores, pero significativamente menores para tareas realizadas con miembros superiores. Se halló un modelo de correlación exponencial negativo entre en tiempo de trabajo, el consumo de oxígeno, y la frecuencia cardiaca, R > 0,9 en todos los casos. Se plantearon 9 ecuaciones de regresión para determinar el tiempo máximo aceptable de trabajo. Conclusiones: El tiempo máximo aceptable de trabajo para miembros inferiores y para todo el cuerpo se comportan de manera similar. El tiempo máximo aceptables de trabajo con miembros superiores es significativamente inferior a los anteriores. La frecuencia cardiaca relativa parece ser el mejor indicador para medir el tiempo máximo aceptables de trabajo en campo.Palabras Clave: consumo de oxígeno, frecuencia cardiaca, carga física de trabajo, tiempo de trabajo aceptable, salud laboral. ABSTRACT Introduction:The physical workload is one of the major risk factors for the workers. At present the proposed methods to assess physical dynamic work load contemplate working with the whole body and not discriminate on body segments. Objective. Determine the maximum acceptable dynamic work time when the work is with the whole body, with the upper and lower limbs. Methods. Oxygen consumption was measurement by ergospirometry and heart rate was monitoring in 30 workers exposed to various loads executed with the whole body, legs and upper limbs. Anaerobic threshold was determined by respiratory quotient, this was used by calculate the acceptable dynamic work time. Results. Statistically significant differences between acceptable dynamic work time for upper limbs and lower limbs were found. Negative exponential correlation model was found between the time the work load and the oxygen consumption and heart rate, R> 0.9 in all cases. Nine regression equations were proposed to determine the acceptable dynamic work time. Conclusions. The acceptable dynamic work time for lower limbs and whole body is similar. The acceptable dynamic work time with upper limbs is significantly lower than the previous. The relative heart rate seems to be the best ...

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“…Additionally, others have suggested that the ideal experimental design when validating metabolic measurement systems would have simultaneous breath-by-breath data collection [11]. The CPX/D has been successfully used as a reference system during rest and varying intensities of exercise elsewhere [7,9,22,23]. …”

Section: Validity Of the Standard System For Comparisonmentioning

confidence: 99%

“…There are a number of automated metabolic measurement systems currently available on the market, each with specific strengths and limitations [7][8][9][10][11]. Typically however they require an integration of equipment, multiple test personnel and significant technical knowledge to run the systems and capture consistent and reliable data.…”

Section: Introductionmentioning

confidence: 99%

Validation of a Simplified, Portable Cardiopulmonary Gas Exchange System for Submaximal Exercise Testing~!2009-10-25~!2010-01-09~!2010-03-17~!

Miller¹,

Woods²,

Olson³

et al. 2010

TOSMJ

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Shape Medical Systems, Inc. has developed a new miniaturized, simplified system for non-invasive cardiopulmonary gas exchange quantification and has targeted their system for submaximal clinical exercise testing in order to abbreviate testing in an expanding clinical market during a climate of escalating health care costs. The focus of the present study was to compare this new device to a validated, standardized system for measures of cardiopulmonary gas exchange. Eighteen healthy adults (10 male/8 female, age 29±7 yr, BMI 23.8±2.4 kg/m 2 ) were brought to the laboratory and instrumented with both measurement systems via in-series pneumotachs. Additionally, the Shape system included a pulse oximeter for heart rate (HR) and oxygen saturation (SaO 2 ), while the standard system included separate 12-lead ECG and oximetry devices. The protocol included 2-min resting breathing, followed by 3-min at each of 3 workloads (50, 70, 125 watts) on a cycle ergometer. Data were collected breath-by-breath and averaged the last 30-sec of each workload. After a 15-min rest period, the pneumotach order was reversed and the study repeated. Since gas exchange data were similar (p>0.05) within a given metabolic testing system between sessions the data were pooled for comparing the Shape and Standard systems. There were no differences (p>0.05) between the systems for oxygen consumption-VO 2 , carbon dioxide production-VCO 2 , ventilation-V E , end tidal CO 2 -PetCO 2 , tidal volume-V T , respiratory rate-fb, and HR at rest or any work load. SaO 2 was slightly, but significantly lower using the Shape embedded oximeter (p<0.05, averaging ~1% across workloads). There were significant correlation coefficients (p<0.001) between the systems for VO 2 (r=0.991), VCO 2 (r=0.986), V E (r=0.995) and PetCO 2 (r=0.953). Bland Altman plots indicated good agreement between systems for the same gas exchange measures, independent of workload. The Shape system was sensitive to small increases in work (50 to 70 watts) and there were no differences in gas exchange measures in a subgroup of subjects (n=4) using a tight fitting mask instead of a mouthpiece (p>0.05). These data suggest that the new, simplified metabolic system developed by Shape Medical Systems, Inc. accurately quantifies key cardiopulmonary variables over a range of workloads, has a coefficient of variation similar to a well validated system and can be used with mouthpiece or mask.

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The Cosmed K4 Telemetry System as an Accurate Device for Oxygen Uptake Measurements during Exercise

Cited by 165 publications

References 2 publications

Reliability and validity of the combined heart rate and movement sensor Actiheart

Reliability and validity of the combined heart rate and movement sensor Actiheart

Tiempo máximo aceptable de trabajo para tareas ejecutadas con miembros superiores e inferiores

Validation of a Simplified, Portable Cardiopulmonary Gas Exchange System for Submaximal Exercise Testing~!2009-10-25~!2010-01-09~!2010-03-17~!

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