0000000000749671
AUTHOR
Saku Levikari
Improving Energy Expenditure Estimation in Wrist-Worn Wearables by Augmenting Heart Rate Data With Heat Flux Measurement
Wearable electronics are often used for estimating the energy expenditure of the user based on heart rate measurement. While heart rate is a good predictor of calorie consumption at high intensities, it is less precise at low intensity levels, which translates into inaccurate results when estimating daily net energy expenditure. In this study, heart rate measurement was augmented with heat flux (HF) measurement, a form of direct calorimetry. A physical exercise test on a group of 15 people showed that HF measurement can improve the accuracy of calorie consumption estimates especially during rest and low-intensity activity when used in conjunction with heart rate information and vital backgr…
Measuring Heart Rate with a Heat Flux Sensor
Different wearable biosignal measurement applications require minimally obtrusive and highly sensitive sensors and methods of transducing the heart pulse into an electric signal. At the same time, the sensors should have minimal power consumption and preferably provide information about more than just the heart rate. In this study, a method employing a heat flux sensor for recording the pulsatile cardiac component of an arterial pulse waveform is presented. The output signals of a conventional photoplethysmography (PPG) sensor and a heat flux sensor were recorded and compared with one another. The results show that a heat flux sensor can be used for measurement of heart pulse, in addition t…