Operation Manual

24 MEDRAD
®
Salient Operation Manual
4.3. Adaptive Flow, Pressure Limit and Over Pressure
At normal injection pressures, the injector will maintain the programmed flow rate. The x-ray image should
display good contrast and opacity.
However, if the fluid path encounters a blockage, or if the connected disposables restrict the flow of contrast, the
syringe pressure will rise. In order to ensure patient safety and protect the disposable system, the flow rate will be
automatically reduced by the injector in order to reduce excessive pressure on the fluid line. Reduction of flow
rate in this condition is known as adaptive flow.
When adaptive flow occurs:
♦ Lower opacification may result, and the images may give an appearance of being “washed
out”.
♦ The injection duration will increase.
♦ The injector beep will lengthen to indicate flow rate reduction is occurring and the LEDs at
the back of the injector head flash orange
Adaptive flow will start as the pressure approaches the pressure limit setting. This pressure limit is a user-
programmable value from 100 to 300 psi in 1 psi increments. If the gradual reduction of flow does not
sufficiently reduce the pressure, a motor stall will result, halting the injection.
If the syringe pressure exceeds the pressure limit by 20%, the injection will halt immediately. This is known as
overpressure.
2
.
The injector is designed to be a regulated fluid delivery device, which monitors pressure for safety reasons.
4.3.1. What to do in the event of adaptive flow reducing image quality
If adaptive flow occurs, and the image quality is reduced, check the fluid path for a blockage. If no blockage
exists in the fluid path, the operator may decrease the flow rate setting or increase the pressure limit setting and
re-arm the system. If the flow rate or pressure limit is to be changed, re-check the physician’s orders.
2
In the event of a sudden blockage during an injection, a very rapid pressure rise may occur. The injector will go into overpressure
and stop without entering the flow reduction process. In this situation, the pressure can exceed the Pressure Limit for very short
periods of time, insufficient to damage disposable sets.
WARNING
Always check the pressure and flow limitations of any disposables to be used with this injector. The
system will remind you of the need to check before an injection can proceed. You are urged to visually
check the packaging of disposables for a pressure and flow rate limit and adjust the injector limits to be
below the limits marked on the packaging.