Section 10 • Delivery Rate Accuracy
58
It is important to note that for the ambIT
®
PIB
v1.5
pumps, virtually all the pressure generated
by the pump is to overcome the pressure drop in the catheter and not in the body, which is
generally a very large low-pressure area. Thus, the basal flow rate and bolus/dose amounts
should always be set at the lowest amount required to achieve the desired effect.
Based on the volumetric accuracy testing carried out, as described above, the ambIT
®
PIB
v1.5
pumps met the volumetric accuracy specifications for flow rate and bolus volumes as shown in
the table found at Section 10.1. Thirty (30) data points were used for each average value found
in Section 10.1 below.
10.1 Data from Volumetric Accuracy Testing
Bolus/Dose
Flow Rate
50 ml
25 ml
0.1 ml
20 ml/hr
10 ml/hr 0.1 ml/hr
Average
2%
2%
-2%
0%v
0%
3%
Standard deviation
2.4%
2.6%
3.8%
2%
2.6%
2%
The volumetric accuracy described in the table above was generated using specific components
and procedures. Thus, if portions of the testing are changed, the volumetric accuracy of the
ambIT® PIB
v1.5
pumps may also change. Factors that may affect volumetric accuracy are
shown below in Section 10.2.
10.2 Factors That May Affect Volumetric Accuracy
Changes
Effect
Comments
Viscosity of
fluid increases
as compared to
water
Volume
infused
decreases
This may result in an under-infusion due to the
speed at which the fluid flows from the fluid
reservoir into the pump. The more viscous the
fluid, the greater the under-infusion and lower
the flow rate.
Syringe is used
as a
fluid reservoir
Volume
infused
decreases
This may result in an under-infusion due to the
speed at which the fluid flows from the syringe
into the pump. The more friction required to move
the syringe, the greater the under-infusion and
lower the flow rate.
Using a catheter
with a gauge
smaller than 20
gauge
Volume
infused
decreases
This may result in an under-infusion due to
increased back pressure caused by the restricted
fluid path.
The pump is designed to be accurate if the back
pressure is below 70 kPa (0.7 bar or 10 psi).
Using a non-
collapsible fluid
reservoir
Volume
infused
decreases
This may result in an under-infusion due to the
vacuum created as the fluid is removed from the
container. The vacuum effect keeps fluid from
flowing into the pump.
