LTV 1200 - Servo

p/n 18603-001, Rev. C LTV
®
1200/1150 Ventilator Service Manual Page 6-29
Servo
The Servo feature allows you to verify certain ventilator functions. When SERVO is on, the
ventilator continuously delivers gas according to the highlighted settings. Gas may be
delivered by:
• turbine speed and flow valve step position
• turbine speed and flow in Lpm
SERVO is used to check ventilator operation or diagnose problems by setting specific
conditions on the ventilator and monitoring the system either externally (e.g. with a flow
meter or pressure gauge) or internally (by using the monitored values under the RT XDCR
DATA menu). For example, delivered flow can be verified
18
by setting the flow to a specified
Lpm
19
and connecting a flow meter to the patient wye. In addition, the monitored flow (FTx)
and other data can be checked under the RT XDCR DATA menu. The servo menu is set up
as follows:
SERVO
SERVO OFF
SERVO ON
To enable the servo functions, press Select while SERVO ON is displayed. The following
displays are turned on (highlighted). Dimmed displays do not affect gas delivery.
Display Purpose
Tidal Volume Sets the flow valve step position
Insp Time Sets the flow in Lpm
O
2
% Sets the delivered O
2
%
High Pres Limit / Low Pres Sets the turbine speed
To turn off the servo functions, press Select while SERVO OFF is displayed. Servo
functions are automatically turned off when you enter the Calibration menu.
To modify a SERVO setting:
1) Press the associated button to select the control.
2) Turn the Set Value knob until the desired setting is displayed.
3) Press the button again or wait 5 seconds to accept the setting.
To select delivery by flow valve step position, press Tidal Volume twice. The controls
for step position and turbine speed will be highlighted to indicate they are active.
To select delivery by Lpm, press Insp. Time twice. The controls for flow, turbine speed
and O
2
% will be highlighted to indicate they are active.
Oxygen blending is active only when delivery by Lpm is selected.
To Home the flow valve, press Manual Breath. After the home is complete, the valve will
return to its previous position.
18
For information on performance tolerances, see Appendix A - Ventilator Specifications in the LTV
®
1200 or the
LTV
®
1150 Ventilator Operator's Manual.
19
Turbine speed must be set to an appropriate value for flow to be delivered accurately.