A combined heart rate and movement sensor: proof of concept and preliminary testing study

Abstract

Objective: Heart rate monitoring has previously been used as a technique for measuring energy expenditure (EE) in ®eld studies. However, the combination of heart rate monitoring with movement sensoring could have theoretical advantages compared to either method used alone. Therefore, this study was undertaken to develop and validate a new combined heart rate monitor and movement sensor instrument (HR M) for measuring EE. Methods: The HR M instrument is a single-piece instrument worn around the chest which records minute-byminute heart rate and movement. Eight subjects underwent an individual calibration in which EE and heart rate were measured at rest and during a sub-maximal bicycle ergometer test. They then wore the HR M for 24 hours in a whole-body calorimeter and underwent a standard protocol including periods of physical activity and inactivity. Minute-by-minute heart rate was converted to EE using individual calibration curves with the motion data discriminating between periods of inactivity and activity at low heart rate levels. EE was also calculated using the HRFlex method which relies on heart rate alone. Both estimates of EE were compared to EE measured in the whole-body calorimeter. Results: The mean percentage error of the HR M method calculating TEE compared with the gold standard of the calorimeter measurement was 0.00% (95% CI of the mean error À0.25, 1.25). The HRFlex method using the heart rate information alone resulted in a mean percentage error of 16.5% (95% CI of the mean error À0.57, 1.76).Conclusions: This preliminary test of HR M demonstrates its ability to estimate EE and the pattern of EE and activity throughout the day. Further validation studies in free-living individuals are necessary. Sponsorship: NJW is an MRC Clinician Scientist Fellow. KLR holds an MRC PhD scholarship. Descriptors: heart rate monitor; movement sensor; energy expenditure

Oxyntomodulin increases energy expenditure in addition to decreasing energy intake in overweight and obese humans: a randomised controlled trial

“…This sensor has recently been developed in order to allow measurement of human energy expenditure in a 'free-living' environment and has been validated against whole-body calorimetry using a fixed activity protocol. 22 It consists of a single-piece waterproof monitor attached to two standard ECG electrodes placed on the subjects' chest. For the current study, the sensor was set to measure movement and heart rate every 30 s over the 4-day-period.…”

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

“…Thus, it remains a continuing goal to develop and evaluate methods for measuring PAEE and its subcomponents that are also affordable and minimally invasive. Methods which integrate physiological and motion detection systems have been identified as a promising research area (LaMonte & Ainsworth, 2001) and previous studies have demonstrated the utility of combined HR and movement measurement to improve precision of PAEE and PAI (Avons et al, 1988;Haskell et al, 1993;Moon & Butte, 1996;Luke et al, 1997;Treuth et al, 1998;Rennie et al, 2000;Strath et al, 2001;Strath et al, 2002;Brage et al, 2003b, c;2004). However, no single commercially available device integrating HR and movement sensing has been described.…”

Comparison of accuracy and precision of heart rate calibration methods to estimate total carbon dioxide production during 13C-breath tests

“…Use of a sigmoid function with smoothed heart rate could improve the estimate of total energy expenditure in studies using simultaneous measurement of heart rate and motion sensing to study both total energy expenditure and patterns of activity in free-living subjects (Rennie et al, 2000;Strath et al, 2002).…”

“…In 13 C-breath tests, it is important to have an accurate estimate of VCO 2 at both resting and nonresting levels of energy expenditure. An improved calibration method would also be useful for studies of total energy expenditure and patterns of activity that utilize simultaneous measurement of heart rate and motion sensing (Rennie et al, 2000;Strath et al, 2002).…”