Fresenius Medical Care 4008 S Service Manual

Chapter 11: Functional description
11-24 Fresenius Medical Care 4008 S (Version V10) SM-EN 7/01.13
11.1.3 Description of the modules
11.1.3.1 Arterial blood pump
The arterial blood pump ensures a sufficient blood flow in the
extracorporeal blood circuit. It is absolutely necessary that sterility is
maintained and that the blood is prevented from becoming
contaminated.
The blood pump is designed as roller pump and integrated into the EBM
of the hemodialysis device. The blood line is installed between a stator,
which, with its rolling surface bent in a circle, represents a thrust
bearing, and a rotor, which is provided with rollers and pivoted in the
stator. The pressure of the rollers causes the development of a narrow
or seal. If the rollers are moving in the direction of delivery, the blood is
pushed in this direction.
A microprocessor controls the stepper motor with quartz accuracy,
depending on the selected delivery rate, the set line diameter, and the
monitor signals.
The pressure measuring equipment comprises of a piezo-resistive
pressure transducer. The pressure- proportional voltage is indicated on
the monitor on a quasi-analog LED scale.
Hex switch: 2 (100 ml/min, special control of the blood pump rate)
Functions of the blood pump:
– RAM and CRC test after power on
– Control and monitoring of the function by a dual-processor system
– Emergency stop in case of an alarm: stop detection
(15 or 30 seconds)
– Setting of the speed to 100 ml/min during priming
– Measurement of the arterial pressure or the Single-Needle pressure
(depending on the model concerned)
– Semi-automatic insertion / removal of the line segment
11.1.3.2 Single-Needle blood pump (optional)
Essentially, the Single-Needle blood pump (SN) is identical with the
arterial blood pump. The difference lies in the Single-Needle control.
During Single-Needle operation, the pressure outlet of the compliance
vessel is connected to the pressure connector of the Single-Needle
pump. The pressure transducer is protected by a hydrophobic filter both
in the external and the internal tubing system.
Hex switch: 3 (100 ml/min, special control of the blood pump rate)
The Single-Needle stroke volume can be set within a range from 10 ml
to 50 ml in increments of 5 ml.
To adjust it, first press the Start/Stop key and the  key
simultaneously.
Then change the value by using the  and  keys.
The lower switching point is fixed to 75 mmHg.

Fresenius Medical Care 4008 S Specifications

General

Brand	Fresenius Medical Care
Model	4008 S
Category	Medical Equipment
Language	English