9-1 
9 Monitoring Respiration (Resp) 
 
 
9.1 Introduction 
Impedance respiration is measured across the thorax. When the patient is breathing or 
ventilated, the volume of air changes in the lungs, resulting in impedance changes between 
the electrodes. Respiration rate (RR) is calculated from these impedance changes, and a 
respiration waveform appears on the patient monitor screen. 
 
 
9.2 Safety Information 
 Warning 
z  When monitoring the patient’s respiration, do not use ESU-proof ECG cables.   
z  If you do not set the detection level for the respiration correctly in manual 
detection mode, it may not be possible for the monitor to detect apnea. If you set 
the detection level too low, the monitor is more likely to detect cardiac activity, and 
to falsely interpret cardiac activity as respiratory activity in the case of apnea.   
z  The respiration measurement does not recognize the cause of apneas. It only 
indicates an alarm if no breath is detected when a pre-adjusted time has elapsed 
since the last detected breath. Therefore, it cannot be used for diagnostic purpose. 
z  If operating under conditions according to the EMC Standard IEC 60601-1-2 
(Radiated Immunity 3V/m), field strengths above 1V/m may cause erroneous 
measurements at various frequencies. Therefore it is recommended to avoid the use 
of electrically radiating equipment in close proximity to the respiration 
measurement unit.