Fluke Biomedical VT Plus HF - Manual (Page 54)

VT Plus HF
Operators Manual
3-4
Barometric Pressure
A barometric pressure measurement is provided by the Analyzer. The barometer can read
absolute pressures from 8 to 18 PSIA. The barometer is also used in the automatic ATP,
BTPS, and STPD conversions for flow and volume measurements. The barometric
pressure signal can be fine tuned using the procedure described in System Setup.
High-Pressure Measurement
The high-pressure measurement is made from a dual-port connection consisting of a (+)
positive and a (-) negative pressure port. The differential pressure range is ±100 psi. This
pressure measurement can be used for any pressure differential or gauge pressure in the
given range. The transducer is capable of measuring fluid pressure on the (+) positive
port as indicated on the label.
Oxygen Concentration
Oxygen concentration is measured through the high-flow port of the system on the rear
panel bulkhead fitting. An integrated sensor measures the oxygen percent of the gas in
the high flow channel of the Analyzer. The range for this sensor is 0 % to 100 %. The
oxygen cell is mounted inside the enclosure on the rear bulkhead for the high-flow
circuit. The fuel cell must be replaced approximately once a year. Oxygen readings are
compensated for airway pressure.
Calculated Breath Parameters
From the primary flow and pressure measurements, the Analyzer is designed to calculate
breath rate, % leak, and base flow. A breath detection algorithm determines the various
phases of a ventilator breath and calculates the parameters listed in Table 3-1.