Alaris™ GP (Guardrails™) Volumetric Pump
Trumpet and Flow Rate Curves
BDDF00535
Issue 1
53/56
Trumpet and Flow Rate Curves
In this Pump, as with all infusion systems, the action of the pumping mechanism and variations cause short-term fluctuations in rate
accuracy .
The following curves show typical performance of the system in two ways: 1) the accuracy of fluid delivery over various time periods is
measured (trumpet curves), and 2) the delay in onset of fluid flow when infusion commences (start-up curves) .
Trumpet curves are named for their characteristic shape . They display discrete 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 effects as represented by the "mouth" of the trumpet .
Knowledge of system accuracy over various observation windows may be of interest when certain drugs are being administered . Short
term fluctuations in rate accuracy may have clinical impact depending on the half-life of the drug being infused and the degree of inter
vascular integration, the clinical effect cannot be determined from the trumpet curves alone .
The start-up curves represent continuous flow 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 . Tests performed per IEC/EN60601-2-24 standard .
Start-up Graph at 0 .1ml/h (Initial Period)
Trumpet Graph at 0 .1ml/h (After 24 Hours)
Flo
w R
at
e (ml/h)
-0.15
-0.10
-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0
10
20
30
40
50
60
70
80
90
100
110
120
Er
ror (%)
-150.00
0.00
150.00
0
5
10
15
20
25
30
35
Time (minutes)
Observation Window (minutes)
Maximum Error
Minimum Error
Overall Mean = -5 .0%
Trumpet Graph at 0 .1ml/h (Initial Period)
Trumpet Graph at 0 .1ml/h (After 72 Hours)
Er
ror (%)
-150
-100
-50
0
50
100
150
0
5
10
15
20
25
30
35
Er
ror (%)
-150.0
0.0
150.0
0
5
10
15
20
25
30
35
Observation Window (minutes)
Observation Window (minutes)
Maximum Error
Minimum Error
Overall Mean = -6 .0%
Maximum Error
Minimum Error
Overall Mean = 4 .0%
Start-up Graph at 1 .0ml/h (Initial Period)
Trumpet Graph at 1 .0ml/h (After 24 Hours)
Flo
w R
at
e (ml/h)
Start-up Graph at 1.0 ml/h (Initial Period)
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0
10
20
30
40
50
60
70
80
90
100
110
120
Er
ror (%)
Trumpet Graph at 1.0 ml/h (After 24 Hours)
-30
-20
-10
0
10
20
30
0
5
10
15
20
25
30
35
Time (minutes)
Observation Window (minutes)
Maximum Error
Minimum Error
Overall Mean = 0 .7%
Note:
The typical flow rate and trumpet curves are achieved using a recommended infusion set .
The plot range has been increased to ± 150%, to allow visualization of the graph .
