 According to recommendations of the World Health Organization WHO the RR should be measured by counting the breaths over a period of 1 minute by counting how many times the chest rises. This should be done when the patient is at rest. This appears impractical due to time consumption and workload for nursing staff in an emergency department. Studies have shown that this fact is a main reason why RR is often not recorded and critical situations might be missed. A prospective study by Lovett et al. demonstrated that the measurement of RR by nursing staff and even by impedance plethysmography as a common used device have a low sensitivity in detecting brady- or tachypnoea. The vital sign measurements may also differ according to observer variability. The approach to use mobile devices for RR measurement has shown encouraging results to improve efficiency in comparison to traditional methods though the field of using mobile devices is still in an experimental stadium. 