Nellcor™ Respiration Rate
ADD-26
Operator’s Manual Addendum
3.
Respiratory sinus arrhythmia (RSA) —
During the respiratory cycle, heart rate
generally increases during inspiration and decreases during expiration. RSA results
in pulse frequency variations. Reference
(d).
Figure 1-17.
Variations of the pleth due to respiration
The Respiration Rate parameter utilizes these subtle pleth variations to
measure respiration rate. Note that the Respiration Rate parameter is an indi-
cator of central ventilatory drive and is not a direct measure of ventilation.
b
a
c
d
