1000DF00480 Issue 2 39/48
Trumpet and Start-Up Curves
DESCRIPTION AND EXPLANATION OF TRUMPET AND START-UP CURVES
In this pump, as with all infusion systems, the action of the pumping mechanism and variations in individual administration sets
cause short-term fluctuations in rate accuracy. The following graphs show typical performance of the system for both Pressure
and Resistance modes in two ways:
•
Accuracy during various time periods over which fluid delivery is measured (trumpet curves).
•
Delay in onset of fluid flow when infusion commences (start-up curves).
Product operation is not affected by the selection of Resistance or High Resistance at 0.1, 1.0, and 25 ml/h; therefore, High
Resistance graphs are not included.
Trumpet curves are named for their characteristic shape. They display discrete accuracy data averaged over particular time
periods or “observation windows”, not continuous data versus operating time. Over long observation windows, short-term
fluctuations have little effect on accuracy, as represented by the flat part of the curve. As the observation window is reduced,
short-term fluctuations have greater effect, as represented by the “mouth” of the trumpet. Knowledge of system accuracy over
vari ous observation windows may be of interest when certain drugs are being administered. Because the clinical impact of
short-term fluctuations on rate accuracy depends on the half-life of the drug be ing infused and on the degree of intravascular
integration, the clinical effect cannot be determined from the trumpet curves alone. Knowledge of the start-up characteristics
should also be considered.
The start-up curves represent continuous flow rate versus operating time for two hours from the start of the infusion. They
exhibit the delay in onset of delivery due to mechanical compliance and provide a visual representation of uniformity. Trumpet
curves are derived from the second hour of this data.
FLOW CHARACTERISTICS UNDER VARYING DELIVERY CONDITIONS
Effects of Pressure Variations
Under conditions of +100 mmHg pressure, the Pump typically exhibits a long-term accuracy offset of approximately -1.4% from
mean values.
Under conditions of +300 mmHg pressure, the Pump typically exhibits a long-term accuracy offset of approximately -1.5% from
mean values.
Under conditions of -100 mmHg pressure, the Pump typically exhibits a long-term accuracy offset of approximately -0.8% from
mean values.
Resulting trumpet observation points typically track those of accuracy; therefore, no significant change in short–term variations
result under these pressure conditions.
Effects of Negative Solution Container Heights
With a negative head height of -0.5 meters, the Pump typically exhibits a long–term accuracy offset of approximately -5.8% from
mean values.
Resulting trumpet observation points typically track those of accuracy; therefore, no significant change in short–term variations
result under negative head height conditions.
Effects of Rate
For applications where flow uniformity is a concern, use of the Pressure Mode at rates of 1.0 ml/h or above is recommended.
A
Tests conducted in accordance with
IEC/EN 60601–2–24
, “Particular requirements for safety of infusion
pumps and controllers” and
AAMI ID26–1998
“Medical electrical equipment - Part
2
: Particular
requirements for the safety of infusion pumps and controllers”, using a Model
72003
Administration Set
(includes Flow Regulator).
