Accuracy of Smart Phone Application to Monitor Heart Rate

Abstract

Smart phones applications to monitor heart rate are very popular. The application examined in this study has millions of installs, with one application boasting of 35 million plus users (application store info). However, there is limited research available on the validity of these applications. An earlier study found a camera-based application to be accurate (McCurley, et al., 2013), but the study examined a single smart-phone platform. PURPOSE: The purpose of this study was to examine the accuracy of a popular heart rate application on two smart phone platforms while resting and during moderate exercise. METHODS: The same heart rate monitor application was chosen for two different technology platforms. The application was required to be free and allow multiple heart rate readings per day. Participants were split into two groups based on technology platform. Both groups were monitored using electrocardiograph (ECG) and the smart phone application seated pre-exercise and during an exercise session on an elliptical machine. Measurements were recorded every minute. Data were analyzed using correlations and t-tests between platforms. All data were analyzed for both seated and exercise heart rate averages. RESULTS: For technology platform 1, heart rate while seated correlation for the application was r = 0.98 (11% missing data) and for platform 2 was r = 0.60 (21% missing data). For platform 1, heart rate during exercise correlation for the application was r = 0.30 (44% missing data) and for platform 2 was r = 0.20 (6% missing data). There was not a significant difference in heart rate while seated, t-test (-1.33), p = .197 nor exercise heart rate, t-test (-1.54), p = .142 when comparing means of the two platforms. CONCLUSIONS: Smart phone applications to monitor heart rate appear to be fairly accurate, particularly at rest. Although these should not be used as a replacement for constant heart rate monitoring tools, they may be useful to allow home monitoring or a quick check of heart rate, particularly when the individual is not moving. Introducing movement reduced the accuracy of the applications and care should be taken when interpreting readings taken during exercise.