LAUSR

This article presents a simple and handy technique to measure respiration rate that employs the magnetic field sensor of a smartphone device. On the abdomen of the subject a tiny and very light permanent magnet is placed and the apparently periodic field—caused by what appears to be periodic breathing of the subject—of the magnet is recorded by the smartphone with the help of its magnetic field sensor. The acquired magnetic field signals allows for the measurement of the period, thus the breathing rate; the value obtained is well within range of normal values. The activity is seen to afford instructional significance in a physics or biology class or, to an extent, in a clinical setting.