Measurements; Flow Measurement; Co 2 Measurement - Dräger Savina 300 Instructions For Use Manual

Principles of operation

Measurements

Flow measurement

Adaptation to ambient conditions
The volume of a gas depends on the ambient
conditions with regard to temperature, pressure,
and humidity. In lung physiology, reference is made
to the conditions inside the lung for the values of
minute volume and tidal volume: 37 °C (99 °F)
body temperature, pressure inside the lungs,
100 % rel. humidity.
Measured values for flow and volume under these
conditions are characterized as BTPS. Medical
gases from cylinders or from a central gas supply
system are dry (approx. 0 % rel. humidity) and are
supplied by the ventilator at 20 °C (68 °F) and
1013 mbar (1013 cmH
flow and volume under these conditions are
characterized as NTPD.
The difference between values measured as NTPD
and BTPS is approx. 12 % at a pressure of
1013 mbar (1013 cmH
Example: 500 mL tidal volume NTPD become
564 mL BTPS when warmed to 37 °C (99 °F) and
humidified to 100 % rel. humidity.
Savina 300 controls tidal volume in such a way that
the set tidal volume value is applied under BTPS
conditions in the lungs.
The expiratory measurement is performed on the
basis of saturated gases at 30 °C (86 °F).
250
O). Measured values for
2
O).
2
CO measurement
2
CO measurement is performed using mainstream
2
sampling with a sampling rate of 20 ms and is
based on an absorption measurement.
A light source generates a spectrum. Two light
detectors record the characteristic absorption
spectrum and supply electrical signals that depend
on the CO concentration.
2
These signals are then evaluated and displayed.
Heating the CO measurement unit prevents
2
condensation.
Instructions for use Savina 300 SW 5.n