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APPENDIX B - Flow Rate Accuracy
SIGMA Manual Number 41018
Revision AR
APPENDIX B - FLOW RATE ACCURACY
Effect of Fluid Container Height
1
,
2
The performance of the infusion pump will be influenced by the forces of gravity on the fluid being
administered to the patient. When a fluid container is positioned above or below the patient’s
administration site, pressure forces associated with the fluid’s head-height (distance measured from
the center of the pumping mechanism to the top of the fluid in the source container) will cause devi-
ations in the nominal specification for device flow rate accuracy. The nominal head-height used for
the flow rate specification is 24” (±61 cm).
Effect of Back Pressure
Positive back pressure can influence the flow rate accuracy of the infusion. Back pressure equivalent
to 300 mmHg may reduce the flow rate causing a deviation in accuracy by -9%. Negative back pres-
sure of -100 mmHg may increase flow rate causing a deviation in accuracy of 7% Hospira and 3%
Baxter IV Sets.
Flow Profile
The SIGMA Spectrum Infusion pump has the following start-up flow rate accuracy curve shape asso-
ciated with stability through time. These graphs represent the variation in flow rate that is recorded
from the time the infusion is started to the end of a two hour period. The graph is intended to give a
picture of the “general stability” with time of the infusion. The graph is commonly called a “start-up
curve”. The techniques and methods of test and generation of this graph are as detailed in IEC
60601-2-24,
Medical electrical equipment – Part 2-24: Particular requirements for the safety of infu-
sion pumps and controllers
.
1.REFERENCE: AAMI ID26:1998, SUB-CLAUSE 50.102
2.LIQUID CONTAINER MUST BE VENTED OR A COLLAPSIBLE BAG