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D. PERFORMANCE CHARACTERISTICS
Direct control is provided for inspiratory and expiratory times, air and oxygen flow
rates, and maximum pressure and PEEP or CPAP levels within the patient circuit.
Oxygen concentration, respiratory rate, tidal volume, and I/E ratio may also be
controlled.
Oxygen concentration…………... variable, 21% to 100%
Respiratory rate…………………. variable, 0 to 120 breaths/min.
Tidal volume……………………… variable, 0 to over 660 ml.
I/E ratio…………………………… variable
Oxygen concentration is determined by the air and oxygen flow rates indicated by
two front panel meters. Flow rates corresponding to a desired oxygen concentration
can be determined by use of CHART A. At extremely low flow rates accuracy may
be reduced; for more accurate determination an auxiliary oxygen analyzer should be
used.
Respiratory rate and I/E ratio are determined by INSP. TIME and EXP. TIME control
settings. These settings are approximate time reference points which are
repeatable within 5%.* For greater accuracy, an external monitoring device may be
used.
The tidal volume, when operated in a time-cycled mode is the product of total flow
and inspiratory time:
TIDAL VOLUME (ml) = TOTAL FLOW RATE (ml/sec) X INSPIRATORY TIME (sec)
NOTE: Flow rate is not Minute Volume
MINUTE VOLUME = TIDAL VOLUME X RESP. RATE
It should be noted that the PIP and PEEP/CPAP control settings are affected by
flow. When flow is increased, the pressure levels set by these controls will increase
somewhat. These changes may be noted on the pressure gauge and the settings
readjusted.
*At elevations above sea level, the intervals set by the INSP. TIME and EXP. TIME controls are increased due to lower
barometric pressure. The difference is about 2½% per 1000' of elevation. With an air supply connected to the POWER
OXYGEN inlet fitting, the time intervals are about 10% less than with pure oxygen connected.
