The accelerometers inside a smartphone can be used to acquire a signal associated with mechanical cardiac activity, generated by the heart’s vibrations at every beat, which can be felt by simply placing the telephone on particular parts of the body, said the study published in the journal Sensors.
In the study, the research team led by Professor Enrico Caiani from Politecnico di Milano in Italy focused on positioning the smartphone on the abdomen, at the belly button, in a prone position, before getting out of bed in the morning.
By suitably processing this signal, measurements can be acquired of the heartbeat rate and status of activation of the sympathetic-vagal balance, associated with the stress level, said the study.
It is possible to check the capacity of the indicators measured by the smartphone to capture the increase in stress, on the one hand, and, on the other hand, to determine the best correspondence of the results with the same observations made using an electrocardiogram taken at the same time.
This result opens new horizons and possibilities for using the smartphone as an instrument readily available for simple self-monitoring of one’s health, said the study.