1. Introduction - Overview
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FLUID PUMP
The roller type peristaltic fluid pump is designed to obtain low hemolysis, consume low
power, is lightweight and very reliable. The pump speed is controlled by the demanded
flow rate that is set by the operator. The pump head can be removed for cleaning. The
pump is mounted near the top of the Control System just below the “Fluid Out" (Out of
Fluid) Detector. The pump tubing is built into the disposable set.
HEATING SYSTEM AND
TEMPERATURE MONITORING
Blood or replacement fluid is warmed as it passes through the heat exchanger. The
heat exchanger consists of a plastic housing holding stainless steel rings used to
transfer the heat to the fluid. Infrared temperature sensors, which are mounted at the
entrance and the exit of the heat exchanger, monitor the temperature of fluid as it enters
and exits the heat exchanger. The temperature of the heated fluid as it leaves the heat
exchanger is displayed on the screen. The system corrects for overheating or
underheating and will shut off and alarm at unsafe conditions. The system is capable of
heating fluids from 10ºC to 37.5ºC at 750 ml/min and 20ºC to 37.5ºC at 1000 ml/min.
PRESSURE MONITORING
A pressure sensor monitors the line pressure of the infusate. Line pressure is directly
influenced by the infusion set used. Larger bore catheters or needles result in lower line
pressure allowing for higher flow rates.
If the sensor detects pressure, which exceeds the limit set by the user, the pump
automatically slows down to maintain the line pressure below the pressure limit. The
pressure limit is set at the factory to the maximum limit of 300 mmHg. If the line
pressure suddenly increases, pumping and heating stop. An alarm sounds and "High
Pressure" is displayed on the screen. High pressure in the line during infusion cannot be
transmitted back to the infusate bag. This high pressure sensing prevents fluid lines from
"blowing out" if blocked.
