Expression MR400 Instructions for Use
Turn the zero reference stopcock "off" to the patient and remove
non‐vented cap from the side port which opens the zero reference
stopcock to air.
The air-fluid interface of the zero reference stopcock should be at or
near the right atrial (mid-axillary) level.
Zero the transducer. Press the Zero All key. (Otherwise, to zero a
single channel, use Zero Set in the respective P1 or P2 menu; see
Zeroing All Pressure Channels (or Zeroing Pressure Channel for a
single channel if Zero Set was used) will be displayed and zeroing
will begin; where, upon completion, Done will be displayed to
If the transducer will not zero and an error condition occurs, verify
that the transducer is being used as described in the manufacturer's
instructions. Press Retry to attempt zeroing again. If the transducer
still does not zero, try another transducer and/or cable; and, if
condition persists, contact technical support or authorized service
Turn the zero reference stopcock "off" to the side port and replace
Attach desired catheter to distal end of monitoring kit and prime,
purging all air bubbles from catheter.
Open stopcock(s) to the catheter. (The catheter tip is now the sys‐
tem air‐fluid interface.)
Place transducer in the position (horizontal plane) it will maintain
during pressure measurement.
Place the catheter tip at the right atrial (mid‐axillary) level.
Monitoring Invasive Blood Pressure 8‐13