15 Impedance Respiration; Overview - GE Healthcare B30 User's Reference Manual

15 Impedance respiration

Overview

Impedance respiration is measured across the thorax. When the patient is breathing or is
ventilated, the volume of air changes in the lungs, resulting in impedance changes between the
electrodes Respiration rate is calculated from these impedance changes, and a respiration
waveform is displayed on the monitor screen.
NOTE: Impedance respiration measurement is intended for patients over three years old.
WARNING This device is not an apnea monitor system intended to alarm primarily
upon the cessation of breathing. In central apnea it indicates an alarm after
a pre-determined time since the last breath detection. Do not attempt to
use it for detecting obstructive or mixed apneas, since respiration
movements and impedance variations may continue in these cases.
WARNING The impedance respiration measurement may cause rate changes in
Minute Ventilation Rate Responsive Pacemakers. Set the pacemaker rate
responsive mode off or turn off the impedance respiration measurement on
the monitor.
WARNING The impedance respiration measurement is inherently very sensitive as it
measures very small physiologic signals (changes of impedance of the
patient's chest area). Conducted RF current above 1 Vrms may cause
erroneous measurements at various frequencies, for example interference
with the signal/waveform leading to respiration rate readings inconsistent
with the patient's true respiration rate. If you notice this, use another form
of respiration monitoring. For further information, see the "Technical
Reference Manual.
Impedance respiration
15-1